IBS patients show frequent fluctuations between loose/watery and hard/lumpy stools: implications for treatment

Shared and distinct aberrations in frontal-striatal system functional patterns among patients with irritable bowel syndrome and major depressive disorder

BACKGROUND

Considering the high comorbidity, shared risk factors, and genetic pathways between irritable bowel syndrome (IBS) and major depressive disorder (MDD), we hypothesized that there would be both shared and disorder-specific alterations in brain function.

METHODS

A total of 39 IBS patients, 39 MDD patients, and 40 healthy controls (HCs) were enrolled and matched for sex, age, and educational level. All subjects underwent resting-state functional MRI. The clinical variables of anxiety, depression, gastrointestinal symptoms and alexithymia were recorded. The 12 subregions of the striatum were employed as seeds to assess their functional connectivity (FC) with every voxel throughout the whole brain.

RESULTS

Compared to HC, IBS and MDD patients exhibited aberrant frontal-striatal circuitry. We observed a common decrease in FC between the dorsal striatum and regions of the hippocampus, sensorimotor cortex, and prefrontal cortex (PFC) in both IBS and MDD patients. Patients with IBS exhibited disorder-specific decreases in FC within the striatum, along with reduced connectivity between the ventral striatum and sensorimotor cortex. In contrast, MDD patients showed disorder-specific hyperconnectivity in the medial PFC-limbic system. Receiver operating characteristic curve analysis showed that frontal-striatal FC values could serve as transdiagnostic markers of IBS and MDD. Within the IBS group, striatal connectivity was not only negatively associated with weekly abdominal pain days but also negatively correlated with the levels of anxiety and alexithymia.

CONCLUSIONS

This exploratory analysis indicated that patients with IBS and MDD exhibited both shared and disorder-specific frontal-striatal circuit impairments, potentially explaining both comorbidity and distinct phenotypes.

Burden of illness and treatment attitudes among participants meeting Rome IV criteria for irritable bowel syndrome: A nationwide survey in the United States

BACKGROUND

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by abdominal pain and altered bowel habits, with patient-perceived dissatisfaction of treatment symptom control. We assessed disease burden, satisfaction with medication use, and impact on activities, in participants with IBS with constipation (IBS-C) and diarrhea (IBS-D).

METHODS

This study assessed data from a large, United States survey of adults querying demographics, comorbid conditions, quality of life, medication use, satisfaction with symptom control, and work productivity. Participants were grouped into the IBS-C or IBS-D cohort if they met Rome IV criteria, with controls matched 1:1 according to age, sex, race, region, and Charlson Comorbidity Index score. All data were self-reported.

KEY RESULTS

Nine hundred and ten participants with IBS-C and 669 with IBS-D were matched to controls. The most reported symptoms were abdominal discomfort for IBS-C and abdominal pain and abdominal discomfort for IBS-D. Among the IBS-C and IBS-D cohorts, 74.2% and 65.9%, respectively, took prescription and/or over-the-counter medication for their symptoms. Respondents were more dissatisfied than satisfied with control of their symptoms. Respondents taking prescription medication(s) with or without over-the-counter medication(s) reported better symptom control than respondents only taking over-the-counter medications (p < 0.001). There was significantly higher mean presenteeism, work productivity loss, and daily activity impairment (p < 0.001 for all) in respondents with IBS compared with controls.

CONCLUSIONS AND INFERENCES

This study provides insight into respondents' experiences of IBS symptoms, including the impact on daily activity, as well as satisfaction with control of symptoms and prescription and over-the-counter medications.

Moving beyond Symptom Criteria to Diagnose and Treat Functional Disorders: Patient-Reported Symptoms of Functional Lower Gastrointestinal Disorders Correlate Poorly with Objective Assessment of Luminal Contents Seen on Intestinal Ultrasound

Background/Objectives: The diagnosis of lower functional gastrointestinal disorders (FGIDs) is currently based on subjective and unreliable patient-reported symptoms, with significant clinical overlap between diagnosed phenotypes. Objective biomarkers are urgently sought. Gastrointestinal ultrasound (GIUS) can objectively and non-invasively assess luminal contents. This study aimed to assess the utility of GIUS in phenotyping patients with lower FGIDs. Methods: Patients with lower FGIDs underwent a GIUS and completed the Rome IV Diagnostic Questionnaire, SAGIS questionnaire, and 100 mm VAS score for overall symptom severity. The faecal loading score (FLS) was obtained using a modified Leech score, where an FLS of >37 was consistent with clinically significant constipation. Results: Eighty-eight patients fulfilled the study requirements. In total, 56 met the Rome IV criteria for irritable bowel syndrome (IBS) subtypes, while 23 met the criteria for functional constipation (FC), 4 for functional diarrhoea (FD), and 5 for other diagnoses. Patients reporting constipation-predominant symptoms had a significantly higher median FLS than those describing diarrhoea-predominant symptoms (FLS = 40 [IQR 20.0-53.3] vs. 13.3 [IQR 6.7-40.0], respectively). However, 27% of patients describing diarrhoea had significant faecal loading on GIUS, and of those who described constipation, 34% did not have significant faecal loading. Sensitivity and specificity for the detection of FLS-indicated constipation by the Rome IV criteria were low at 59% and 66%, respectively. Conclusions: The symptom-based diagnosis of FGID subtypes based on the Rome IV criteria is a poor predictor of faecal loading. These findings should prompt further exploration of the limitations of symptom-based assessment and a shift towards physiological assessment of patients with FGIDs such as gastrointestinal ultrasound to develop more targeted therapy. Future research is underway to determine if targeting objective physiological endpoints results in improved clinical outcomes.

ReFerm®: a postbiotic fermented oat gruel composition is reducing mast cell degranulation in the colon of patients with irritable bowel syndrome

Background

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder that affects ~4% of the global population. ReFerm® is a postbiotic product derived from oat gruel fermented with Lactobacillus plantarum 299v, and it has been shown to have beneficial effects on intestinal permeability in patients with IBS. In this study, we investigated the effects of ReFerm® on regulators of intestinal permeability, namely mast cells and enteric glial cells.

Materials and methods

A total of 30 patients with moderate to severe IBS were treated with an enema containing ReFerm® or a placebo twice daily. The patients underwent sigmoidoscopy with biopsies obtained from the distal colon at baseline and after 14 days of treatment. These biopsies were processed in two ways: some were fixed, embedded in paraffin, sectioned, and stained for mast cells and enteric glial cells; others were cryopreserved, lysed, and subjected to Western blotting to analyze the same markers.

Results

Treatment with ReFerm®, but not the placebo, significantly reduced mast cell tryptase protein levels in the biopsy lysates. Although the number of mast cells remained unchanged in colonic biopsies, ReFerm® treatment significantly reduced mast cell degranulation, a result not observed in the placebo group. Neither ReFerm® or placebo treatment had an impact on total protein levels or the number of enteric glial cells in the biopsies.

Conclusion

ReFerm® treatment significantly reduced both total mast cell tryptase levels and the degranulation of mast cells in colonic biopsies from patients with IBS, suggesting a decrease in mast cell activity as a potential mechanism underlying the beneficial effects of ReFerm®. However, further research is required to assess the molecular mechanisms through which ReFerm® operates in the colons of patients with IBS.

Clinical trial registration

https://clinicaltrials.gov, identifier: NCT05475314.

Intestinal Permeability, Irritable Bowel Syndrome with Constipation, and the Role of Sodium-Hydrogen Exchanger Isoform 3 (NHE3)

Increased intestinal permeability has been identified as one of the many pathophysiological factors associated with the development of irritable bowel syndrome (IBS), a common disorder of gut-brain interaction. The layer of epithelial cells that lines the intestine is permeable to a limited degree, and the amount of paracellular permeability is tightly controlled to enable the absorption of ions, nutrients, and water from the lumen. Increased intestinal permeability to macromolecules can be triggered by a variety of insults, including infections, toxins from food poisoning, or allergens, which in turn cause an inflammatory response and are associated with abdominal pain in patients with IBS. This review article discusses increased intestinal permeability in IBS, focusing on IBS with constipation (IBS-C) through the lens of a patient case with a reported prior diagnosis of "leaky gut syndrome" upon initial contact with a gastrointestinal specialist. We review advantages and disadvantages of several methods of measuring intestinal permeability in patients and discuss when measuring intestinal permeability is appropriate in the therapeutic journey of patients with IBS-C. Furthermore, we discuss a possible mechanism of restoring the intestinal barrier to its healthy state through altering intracellular pH by inhibiting sodium-hydrogen exchanger isoform 3 (NHE3). Tenapanor is a minimally absorbed, small-molecule inhibitor of NHE3 that has been approved by the US Food and Drug Administration for the treatment of IBS-C in adults. Preclinical studies showed that tenapanor may restore the intestinal barrier in IBS-C by affecting the conformation of tight junction proteins via NHE3 inhibition to block the paracellular transport of macromolecules from the intestinal lumen. Testing for increased permeability in patients with IBS-C who experience abdominal pain may help inform the choice of therapeutics and alter patients' misconceptions about "leaky gut syndrome".

Temporal stability of fecal metabolomic profiles in irritable bowel syndrome

BACKGROUND

The potential of the fecal metabolome to serve as a biomarker for irritable bowel syndrome (IBS) depends on its stability over time. Therefore, this study aimed to determine the temporal dynamics of the fecal metabolome, and the potential relationship with stool consistency, in patients with IBS and healthy subjects.

METHODS

Fecal samples were collected in two cohorts comprising patients with IBS and healthy subjects. For Cohort A, fecal samples collected during 5 consecutive days were analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS). For Cohort B, liquid chromatography-MS (LC-MS) was used to analyze fecal samples collected at week 0 (healthy and IBS) and at week 4 (patients only). Stool consistency was determined by the Bristol Stool Form scale.

KEY RESULTS

Fecal samples were collected from Cohort A (seven healthy subjects and eight IBS patients), and Cohort B (seven healthy subjects and 11 IBS patients). The fecal metabolome of IBS patients was stable short-term (Cohort A, 5 days and within the same day) and long-term (Cohort B, 4 weeks). A similar trend was observed over 5 days in the healthy subjects of Cohort A. The metabolome dissimilarity was larger between than within participants over time in both healthy subjects and IBS patients. Further analyses showed that patients had greater range of stool forms (types) than healthy subjects, with no apparent influence on metabolomic dynamics.

CONCLUSION & INFERENCES

The fecal metabolome is stable over time within IBS patients as well as healthy subjects. This supports the concept of a stable fecal metabolome in IBS despite fluctuations in stool consistency, and the use of single timepoint sampling to further explore how the fecal metabolome is related to IBS pathogenesis.

The Variability of Tryptophan Metabolism in Patients with Mixed Type of Irritable Bowel Syndrome

Patients with a mixed type of irritable bowel syndrome (IBS-M) experience constipation and diarrhea, which alternate between weeks or months. The pathogenesis of this syndrome is still little understood. The aim of the study was mainly to evaluate the urinary excretion of selected tryptophan (TRP) metabolites during the constipation and diarrhea periods of this syndrome. In 36 patients with IBS-M and 36 healthy people, serum serotonin level was measured by ELISA and urinary levels of 5-hydroxyindoleacetic acid (5-HIAA), kynurenine (KYN) and indican (3-IS) were determined using the LC-MS/MS method. The levels of all above metabolites were higher in the patient group, and increased significantly during the diarrheal period of IBS-M. In particular, the changes concerned 5-HIAA (3.67 ± 0.86 vs. 4.59 ± 0.95 mg/gCr, p < 0.001) and 3-IS (80.2 ± 17.4 vs. 93.7 ± 25.1 mg/g/Cr, p < 0.001). These changes coexisted with gut microbiome changes, assessed using hydrogen-methane and ammonia breath tests. In conclusion, the variability of TRP metabolism and the gut microbiome may cause the alternation of IBS-M symptoms.

Exploring new subgroups for irritable bowel syndrome using a machine learning algorithm

Irritable bowel syndrome (IBS) is a complicated gut-brain axis disorder that has typically been classified into subgroups based on the major abnormal stool consistency and frequency. The presence of components other than lower gastrointestinal (GI) symptoms, such as psychological burden, has also been observed in IBS manifestations. The purpose of this research is to redefine IBS subgroups based on upper GI symptoms and psychological factors in addition to lower GI symptoms using an unsupervised machine learning algorithm. The clustering of 988 individuals who met the Rome III criteria for diagnosis of IBS was performed using a mixed-type data clustering algorithm. Nine sub-groups emerged from the proposed clustering: (I) High diarrhea, pain, and psychological burden, (II) High upper GI, moderate lower GI, and psychological burden, (III) High psychological burden and moderate overall GI, (IV) High constipation, moderate upper GI, and high psychological burden, (V) moderate constipation and low psychological burden, (VI) High diarrhea and moderate psychological burden, (VII) moderate diarrhea and low psychological burden, (VIII) Low overall GI, and psychological burden, (IX) Moderate lower GI, and low psychological burden. The proposed procedure led to the discovery of new homogeneous clusters in addition to certain well-known Rome sub-types for IBS.

Quantum chemical, spectroscopic and molecular docking studies on methyl 2-chloro-6-methyl pyridine-4-carboxylate: A potential inhibitor for irritable bowel syndrome

The methyl 2-chloro-6-methyl pyridine-4-carboxylate (MCMP) was studied using quantum chemical density functional theory (DFT) approach. The DFT/B3LYP method with cc-pVTZ basis set was employed to obtain the optimized stable structure and vibrational frequencies. The potential energy distribution (PED) calculations were used to assign the vibrational bands. The ¹³C NMR spectrum of MCMP molecule was simulated by the Gauge-Invariant-atomic orbital (GIAO) method using DMSO solution and the corresponding chemical shift values were calculated and observed. The maximum absorption wavelength was obtained using TD-DFT method and were compared with the experimental values. The bioactive nature of the MCMP compound was identified using the FMO analysis. The possible sites of electrophilic and nucleophilic attack were predicted using the MEP analysis and local descriptor analysis. The pharmaceutical activity of the MCMP molecule is validated through the NBO analysis. The molecular docking analysis confirms that the MCMP molecule can be used in the drug designing for the treatment of irritable bowel syndrome (IBS).

Randomised clinical trial: efficacy and safety of the live biotherapeutic product MRx1234 in patients with irritable bowel syndrome

BACKGROUND

MRx1234 is a live biotherapeutic product that contains a strain of Blautia hydrogenotrophica. It is in development for the treatment of irritable bowel syndrome (IBS).

AIMS

To assess the efficacy and safety of MRx1234 in patients with IBS with predominant constipation (IBS-C) or diarrhoea (IBS-D) METHODS: We conducted a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial. Patients aged 18-70 years in two parallel cohorts (IBS-C; IBS-D) were randomised (1:1) to MRx1234 or placebo for 8 weeks. The primary efficacy endpoint was overall responder rate-a composite of improved bowel habit (IBS-C: stool frequency; IBS-D: stool consistency) and abdominal pain intensity-for ≥50% of the treatment period in each cohort. Statistical testing was at a one-sided 0.10 significance level.

RESULTS

Of 366 randomised patients (164 IBS-C; 202 IBS-D), 365 received any study medication (177 MRx1234, 188 placebo). Numerically, although not statistically significantly different, more patients who received MRx1234 than placebo were overall responders in the IBS-C (25.0% vs. 17.1%) and IBS-D (23.4% vs. 17.8%) cohorts. Similar results were observed in the additional combined cohort analysis (24.1% vs. 17.5%; p = 0.063). For the components of the primary endpoint, significantly more patients on MRx1234 than placebo reported improvement in bowel habit in the IBS-C, IBS-D and combined cohorts, while improvements in abdominal pain were observed in each cohort. The safety profile of MRx1234 was similar to placebo.

CONCLUSIONS

MRx1234 has the potential to become a novel, safe treatment option for patients with IBS-C or IBS-D, and for those who have mixed symptoms or transition between subtypes.

CLINICALTRIALS

gov #NCT03721107.

A postbiotic fermented oat gruel may have a beneficial effect on the colonic mucosal barrier in patients with irritable bowel syndrome

Background

Impaired intestinal permeability and microbial dysbiosis are important pathophysiological mechanisms underlying irritable bowel syndrome (IBS). ReFerm^®, also called Profermin^®, is a postbiotic product of oat gruel fermented with Lactobacillus plantarum 299v. In this study, we investigated whether ReFerm^® has a beneficial effect on the intestinal epithelial barrier function in patients with IBS.

Materials and methods

Thirty patients with moderate to severe IBS-diarrhoea (IBS-D) or IBS-mixed (IBS-M) were treated with enema containing ReFerm^® or placebo. The patients underwent sigmoidoscopy with biopsies obtained from the distal colon at baseline and after 14 days of treatment with ReFerm^® or placebo twice daily. The biopsies were mounted in Ussing chambers, and paracellular and transcellular permeabilities were measured for 120 min. In addition, the effects of ReFerm^® or placebo on the epithelial barrier were investigated in vitro using Caco-2 cells.

Results

ReFerm^® reduced paracellular permeability (p < 0.05) and increased transepithelial resistance (TER) over time (p < 0.01), whereas the placebo had no significant effect in patients. In ReFerm^®-treated Caco-2 cells, paracellular and transcellular permeabilities were decreased compared to the control (p < 0.05) and placebo (p < 0.01). TER was increased in Caco-2 ReFerm^®-treated cells, and normalised TER was increased in ReFerm^®-treated Caco-2 cells compared to control (p < 0.05) and placebo-treated (p < 0.05) cells.

Conclusion

ReFerm^® significantly reduced paracellular permeability and improved TER in colonic biopsies collected from patients with IBS and in a Caco-2 cell model. Our results offer new insights into the potential benefits of ReFerm^® in IBS management. Further studies are needed to identify the molecular mechanisms underlying the barrier-protective properties of ReFerm^®.

Clinical trial registration

[https://clinicaltrials.gov/], identifier [NCT05475314].

The Potential Role of Human Milk Oligosaccharides in Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is the most common gastrointestinal (GI) disorder in Western populations and therefore a major public health/economic concern. However, despite extensive research, psychological and physiological factors that contribute to the aetiology of IBS remain poorly understood. Consequently, clinical management of IBS is reduced to symptom management through various suboptimal options. Recent evidence has suggested human milk oligosaccharides (HMOs) as a potential therapeutic option for IBS. Here, we review literature concerning the role of HMOs in IBS, including data from intervention and in vitro trials. HMO supplementation shows promising results in altering the gut microbiota and improving IBS symptoms, for instance by stimulating bifidobacteria. Further research in adults is required into HMO mechanisms, to confirm the preliminary results available to date and recommendations of HMO use in IBS.

Virtual Tai Chi program for patients with irritable bowel syndrome with constipation: Proof-of-concept feasibility trial

BACKGROUND

Satisfaction with current treatment options for irritable bowel syndrome with constipation (IBS-C) is low, with many patients turning to complementary treatments. Tai Chi is a mind-body medicine practice with proven efficacy in other functional disorders. As a proof-of-concept, we tested the feasibility and preliminary clinical outcomes associated with a Tai Chi program designed for IBS-C.

METHODS

A total of 27 IBS-C patients participated in a single-arm trial of 8 sessions of Tai Chi delivered weekly over 7 weeks via live videoconferencing in group format. Clinical improvement was assessed via change in IBS Symptom Severity Score (IBS-SSS) from baseline to 4 weeks posttreatment (week 11) with secondary outcomes exploring symptom ratings, IBS-related quality of life (IBS-QOL), GI-specific anxiety, abdominal distention, and psychological factors.

KEY RESULTS

Despite substantial dropout (n = 7; 26%), the treatment protocol had moderate to excellent feasibility for other criteria. Treatment satisfaction was excellent. Exit interviews confirmed high satisfaction with the program among completers, but a high burden of data collection was noted. One participant experienced an adverse event (mild, exacerbation of sciatica). There was a significant improvement in intra-individual IBS-SSS between baseline and posttreatment (average change -66.5, 95% CI -118.6 to -14.3, p = 0.01). Secondary outcomes were notable for improvements in other IBS symptom scoring measures, IBS-QOL, measured abdominal diameter, and leg strength.

CONCLUSIONS AND INFERENCES

Our data provide preliminary evidence of the feasibility of a Tai Chi intervention for IBS-C, show promise for improving outcomes, and identify more streamlined data collection as an area for further program improvement.

Irritable bowel syndrome in adults: Prevalence and risk factors

Introduction

The prevalence of irritable bowel syndrome (IBS) ranges from 7 to 18% over the world. We aimed to assess the prevalence and risk factors of irritable bowel syndrome in adults.

Methodology

We conducted a cross-sectional study of IBS prevalence and risk factors from March to May 2022 at KRL Hospital Islamabad. 300 people were given Pre-validated Performa's. Our research adheres to the principles outlined in the Helsinki Declaration. The PSS was used to measures how much stress a person has felt in the past month.

The higher the score, the more stressed the person appears to be. A variety of mental health disorders can be evaluated using this method. Data on dietary and lifestyle factors associated with IBS for the last 12 months was also collected from the participants.

Results

The majority of patients, 70%, were classed as Grade 1 and 146 (48.66%) reported abdominal pain associated with defecation. 162 (54%) individuals reported high levels of tea consumed, 81 (27%) consumed coffee and 57 (19%) reported carbonated drinks consumed. 139 individuals reported having Vigorous-Intensity activity, out of which 69 (49.64%) spend 60 min of vigorous activity in a day.

Conclusion

Screening patients for IBS on a regular basis is critical, especially in the younger demographic. If a patient experiences any symptoms of IBS, they should contact their doctor immediately. Consider the care of patients with chronic gastrointestinal complaints, particularly in women and those at greater risk of developing the illness.

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Perceived Stress Scale (PSS) measures how much stress a person has felt in the past month.

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The Chalder Fatigue Scale (CFS) is used to measure fatigue.

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We recommend the younger population to be screened for IBS on a regular basis.

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Persistent gastrointestinal symptoms, especially women and those at high risk of the condition, it is critical to take this into account.

Protocol for faecal microbiota transplantation in irritable bowel syndrome: the MISCEAT study - a randomised, double-blind cross-over study using mixed microbiota from healthy donors

INTRODUCTION

Several studies have demonstrated dysbiosis in irritable bowel syndrome (IBS). Therefore, faecal microbiota transplantation, whose effect and safety have been proven in Clostridioides difficile infections, may hold promise in other conditions, including IBS. Our study will examine the effectiveness of stool transfer with artificially increased microbial diversity in IBS treatment.

METHODS AND ANALYSIS

A three-group, double-blind,randomised, cross-over, placebo-controlled study of two pairs of gut microbiota transfer will be conducted in 99 patients with diarrhoeal or mixed type of IBS. Patients aged 18-65 will be randomised into three equally sized groups: group A will first receive two enemas of study microbiota mixture (deep-frozen stored stool microbiota mixed from eight healthy donors); after 8 weeks, they will receive two enemas with placebo (autoclaved microbiota mixture), whereas group B will first receive placebo, then microbiota mixture. Finally, group C will receive placebos only. The IBS Severity Symptom Score (IBS-SSS) questionnaires will be collected at baseline and then at weeks 3, 5, 8, 11, 13, 32. Faecal bacteriome will be profiled before and regularly after interventions using 16S rDNA next-generation sequencing. Food records, dietary questionnaires, anthropometry, bioimpedance, biochemistry and haematology workup will be obtained at study visits during the follow-up period. The primary outcome is the change in the IBS-SSS between the baseline and 4 weeks after the intervention for each patient compared with placebo. Secondary outcomes are IBS-SSS at 2 weeks after the intervention and 32 weeks compared with placebo and changes in the number of loose stools, Bristol stool scale, abdominal pain and bloating, anthropometric parameters, psychological evaluation and the gut microbiome composition.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of Thomayer University Hospital, Czechia (G-18-26); study results will be published in peer-reviewed journals and presented at international conferences and patient group meetings.

TRIAL REGISTRATION NUMBER

NCT04899869.

Characteristics of, and natural history among, individuals with Rome IV functional bowel disorders

BACKGROUND

Little is known about the natural history of functional bowel disorders using Rome IV criteria. We examined these issues in a longitudinal follow-up study.

METHODS

We collected complete demographic, gastrointestinal symptom, and psychological comorbidity data at baseline from 1372 adults who met Rome IV criteria for one of the five functional bowel disorders. At 12 months, we collected data regarding gastrointestinal symptoms, psychological comorbidity, consultation behavior, and treatment commenced. We examined prognosis and stability of all five functional bowel disorders.

KEY RESULTS

At baseline, 811 (59.1%) individuals met Rome IV criteria for irritable bowel syndrome (IBS), 76 (5.5%) functional constipation (FC), 199 (14.5%) functional diarrhea (FDr), 130 (9.5%) functional abdominal bloating or distension (FABD), and 156 (11.4%) unspecified functional bowel disorder (UFBD). In total, 782 (57.0%) were successfully followed up. Individuals with IBS at baseline were significantly more likely to report symptoms compatible with anxiety, depression, or somatoform-type behavior (p < 0.001 for all analyses) at baseline and follow-up compared with those with the other four functional bowel disorders. IBS was the most stable functional bowel disorder; 319 (70.6%) of 452 participants still met criteria for IBS at 12 months, compared with 14 (34.1%) of 41, 43 (35.5%) of 121, 26 (33.8%) of 77, and 37 (40.7%) of 91 for FC, FDr, FABD, and UFBD, respectively (p < 0.001).

CONCLUSIONS AND INFERENCES

Individuals with Rome IV-defined IBS exhibited higher levels of anxiety, depression, or somatoform-type symptom reporting. IBS was the most stable and the likeliest disorder that the other four functional bowel disorders would fluctuate to.

Gut microbiota signatures and modulation in irritable bowel syndrome

Irritable bowel syndrome (IBS) affects approximately one tenth of the general population and is characterized by abdominal pain associated with abnormalities in bowel habits. Visceral hypersensitivity, abnormal intestinal motor function, mucosal immune activation, and increased intestinal permeability concur to its pathophysiology. Psychological factors can influence symptom perception at the central nervous system level. In addition, recent evidence suggests that dysbiosis may be a key pathophysiological factor in patients with IBS. Increasing understanding of the pathophysiological mechanisms translates into new and more effective therapeutic approaches. Indeed, in line with this evidence, IBS therapies nowadays include agents able to modulate gut microbiota function and composition, such as diet, prebiotics, probiotics, and antibiotics. In addition, in the last decade, an increasing interest in fecal microbiota transplantation has been paid. An in-depth understanding of the intestinal microenvironment through accurate faucal microbiota and metabolite analysis may provide valuable insights into the pathophysiology of IBS, finally shaping new tailored IBS therapies.

Review article: irritable bowel syndrome: natural history, bowel habit stability and overlap with other gastrointestinal disorders

Symptoms of irritable bowel syndrome (IBS) characteristically fluctuate over time. We aimed to review the natural history of IBS and IBS subgroups including bowel habit disturbances, and the overlap of IBS with other gastrointestinal disorders. The community incidence of IBS is approximately 67 per 1000 person years. The prevalence of IBS is stable over time because symptoms fluctuate and there is a portion who experience resolution of their GI symptoms similar in number to those developing new-onset IBS. The proportion who report resolution of symptoms varies amongst population-based studies from 17% to 55%. There is evidence of substantial movement between subtypes of IBS. For example in a clinical trial cohort, only one in four patients retained their baseline classification throughout the study periods, two in three moved between IBS-C (constipation) and IBS-M (mixed), while over half switched between IBS-D (diarrhoea) and IBS-M. The least stable group was IBS-M. There are very limited data on drivers of bowel habit change in IBS. There are emerging evidence fluctuations in intestinal immune activity might account for symptom variability over time. It is of clinical importance to recognise the substantial overlap of IBS symptoms with other gastrointestinal syndromes including gastro-oesophageal reflux disease. This is important to ensure the correct clinical diagnosis of IBS is made and patients are not over investigated. Knowledge of the natural history, stability of subgroups and overlap of IBS with other gastrointestinal conditions should be considered in therapeutic decision making.

Understanding the physiology of human defaecation and disorders of continence and evacuation

The act of defaecation, although a ubiquitous human experience, requires the coordinated actions of the anorectum and colon, pelvic floor musculature, and the enteric, peripheral and central nervous systems. Defaecation is best appreciated through the description of four phases, which are, temporally and physiologically, reasonably discrete. However, given the complexity of this process, it is unsurprising that disorders of defaecation are both common and problematic; almost everyone will experience constipation at some time in their life and many will develop faecal incontinence. A detailed understanding of the normal physiology of defaecation and continence is critical to inform management of disorders of defaecation. During the past decade, there have been major advances in the investigative tools used to assess colonic and anorectal function. This Review details the current understanding of defaecation and continence. This includes an overview of the relevant anatomy and physiology, a description of the four phases of defaecation, and factors influencing defaecation (demographics, stool frequency/consistency, psychobehavioural factors, posture, circadian rhythm, dietary intake and medications). A summary of the known pathophysiology of defaecation disorders including constipation, faecal incontinence and irritable bowel syndrome is also included, as well as considerations for further research in this field.

Blue poo: impact of gut transit time on the gut microbiome using a novel marker

BACKGROUND AND AIMS

Gut transit time is a key modulator of host-microbiome interactions, yet this is often overlooked, partly because reliable methods are typically expensive or burdensome. The aim of this single-arm, single-blinded intervention study is to assess (1) the relationship between gut transit time and the human gut microbiome, and (2) the utility of the 'blue dye' method as an inexpensive and scalable technique to measure transit time.

METHODS

We assessed interactions between the taxonomic and functional potential profiles of the gut microbiome (profiled via shotgun metagenomic sequencing), gut transit time (measured via the blue dye method), cardiometabolic health and diet in 863 healthy individuals from the PREDICT 1 study.

RESULTS

We found that gut microbiome taxonomic composition can accurately discriminate between gut transit time classes (0.82 area under the receiver operating characteristic curve) and longer gut transit time is linked with specific microbial species such as Akkermansia muciniphila, Bacteroides spp and Alistipes spp (false discovery rate-adjusted p values <0.01). The blue dye measure of gut transit time had the strongest association with the gut microbiome over typical transit time proxies such as stool consistency and frequency.

CONCLUSIONS

Gut transit time, measured via the blue dye method, is a more informative marker of gut microbiome function than traditional measures of stool consistency and frequency. The blue dye method can be applied in large-scale epidemiological studies to advance diet-microbiome-health research. Clinical trial registry website https://clinicaltrials.gov/ct2/show/NCT03479866 and trial number NCT03479866.

Chronic constipation in adults: Contemporary perspectives and clinical challenges. 1: Epidemiology, diagnosis, clinical associations, pathophysiology and investigation

BACKGROUND

Chronic constipation is a prevalent disorder that affects patients' quality of life and consumes resources in healthcare systems worldwide. In clinical practice, it is still considered a challenge as clinicians frequently are unsure as to which treatments to use and when. Over a decade ago, a Neurogastroenterology & Motility journal supplement devoted to the investigation and management of constipation was published (2009; 21 (Suppl.2)). This included seven articles, disseminating all themes covered during a preceding 2-day meeting held in London, entitled "Current perspectives in chronic constipation: a scientific and clinical symposium." In October 2018, the 3rd London Masterclass, entitled "Contemporary management of constipation" was held, again over 2 days. All faculty members were invited to author two new review articles, which represent a collective synthesis of talks presented and discussions held during this meeting.

PURPOSE

This article represents the first of these reviews, addressing epidemiology, diagnosis, clinical associations, pathophysiology, and investigation. Clearly, not all aspects of the condition can be covered in adequate detail; hence, there is a focus on particular "hot topics" and themes that are of contemporary interest. The second review addresses management of chronic constipation, covering behavioral, conservative, medical, and surgical therapies.

Longitudinal follow-up of a novel classification system for irritable bowel syndrome: natural history and prognostic value

BACKGROUND

Conventionally, irritable bowel syndrome (IBS) is subgrouped using predominant stool form, yet it is a complex disorder, with multiple biopsychosocial contributors. We previously derived and validated a latent class model subgrouping people with IBS into seven clusters based on gastrointestinal and extraintestinal symptoms and psychological profile.

AIMS

To conduct longitudinal follow-up examining the natural history and prognostic value of these clusters.

METHODS

Participants completed a 12-month follow-up questionnaire. We applied our model to these data, comparing cluster membership between the two time points in those still meeting Rome IV criteria at follow-up, including stratifying the analysis by predominant stool pattern, and level of psychological burden, at baseline. We examined whether baseline cluster predicted the course of IBS, and whether starting new treatment was associated with changing cluster.

RESULTS

Eight hundred and eleven participants met Rome IV criteria for IBS at baseline, of whom 452 (55.7%) responded, and 319 (70.6%) still met Rome IV criteria for IBS at follow-up. Of these, 172 (53.9%) remained in the same IBS cluster as at baseline and 147 changed cluster. Cluster membership stratified according to psychological comorbidity was more stable; 84% of those in a cluster with high psychological burden at baseline remained in such a cluster at follow-up. People in clusters with high psychological burden at baseline had more severe symptoms (P < 0.001), received a higher mean number of subsequent treatments (P < 0.001), and were more likely to consult a doctor than people in clusters with low psychological burden (P < 0.001). There was no significant association between starting a new treatment and changing cluster at follow-up.

CONCLUSIONS

Longitudinal follow-up demonstrated little transition between clusters with respect to psychological burden, and these appeared to predict disease course. Directing treatment according to cluster, including earlier use of psychological therapies, and exploring how this approach influences outcomes in IBS, should be examined.

Subtypes and Severity of Irritable Bowel Syndrome Are Not Related to Patients' Self-Reported Dietary Triggers: Results From an Online Survey in Dutch Adults

BACKGROUND

Diet plays an important role in symptom management of irritable bowel syndrome (IBS). However, current diet therapies are not optimal nor successful for everyone.

OBJECTIVE

To investigate whether subgroups based on IBS subtypes or severity identify different self-reported dietary triggers, and whether these are associated with severity and psychological factors.

DESIGN

Online cross-sectional survey PARTICIPANTS: Patients with IBS (n = 1601) who fulfilled the Rome IV criteria or had an IBS diagnosis.

MAIN OUTCOMES

Self-reported response to 44 preselected dietary triggers, IBS quality of life, and anxiety and depression. Subgroups were based on subtypes or severity.

STATISTICAL ANALYSIS

Response to dietary triggers was analyzed using multiple correspondence analysis. Moreover, a food score was calculated to quantify the number and severity of responses to dietary triggers.

RESULTS

Response to greasy foods, onions, cabbage, and spicy and fried foods were mentioned most often (ranging between 55% and 65%). Response to dietary triggers differed between subtypes and severity groups, but absolute differences were small. Multiple correspondence analysis did not reveal clustering between dietary triggers, and ellipses for the subtypes overlapped. Some clustering was seen when ellipses were drawn for severity, which indicates that severity explained a fraction of the variation in response to dietary triggers, and subtypes did not. The food score was not significantly different between subtypes but was significantly higher with higher levels of severity (mild = 20.9 ± 17, moderate = 29.2 ± 19, severe = 37.9 ± 20, P < .001), having depressive (no = 31.4 ± 20, yes = 37.4 ± 20, P < .001) or anxious symptoms (no = 30.7 ± 20, yes = 35.2 ± 20, P < .001), and lower quality of life (lower quality of life = 38.5 ± 19, higher quality of life = 26.5 ± 19, P < .001).

CONCLUSION

Patients with different IBS subtypes or IBS severity do not identify different self-reported dietary triggers. Patients with more severe IBS and who experience anxiety or depression tend to have severe responses to more dietary triggers. IBS severity seems a better classifier than Rome IV criteria regarding diet. Dietary treatment needs to be individualized under guidance of a dietitian.

Impact of Diet on Symptoms of the Irritable Bowel Syndrome

Irritable bowel syndrome (IBS), with its key features of abdominal pain and disturbed bowel habit, is thought by both patients and clinicians to be strongly influenced by diet. However, the complexities of diet have made identifying specific food intolerances difficult. Eating disorders can masquerade as IBS and may need specialist treatment. While typical food allergy is readily distinguished from IBS, the mechanisms of gut-specific adverse reactions to food are only just being defined. These may include gut-specific mast cell activation as well as non-specific activation by stressors and certain foods. Visceral hypersensitivity, in some cases mediated by mast cell activation, plays a key part in making otherwise innocuous gut stimuli painful. Rapidly fermented poorly absorbed carbohydrates produce gaseous distension as well as short-chain fatty acids and lowering of colonic pH which may cause symptoms in IBS patients. Limiting intake of these in low FODMAP and related diets has proven popular and apparently successful in many patients. Existing diet, colonic microbiota and their metabolic products may be helpful in predicting who will respond. Wheat intolerance may reflect the fact that wheat is often a major source of dietary FODMAPs. It may also be either a forme fruste of coeliac disease or non-specific immune activation. Wheat exclusion can be successful in some of these patients. More research is needed to fully understand the mechanisms of food intolerances and how to best ameliorate them in a personalised medicine approach to diet in IBS.

A Novel Method to Classify and Subgroup Patients With IBS Based on Gastrointestinal Symptoms and Psychological Profiles

INTRODUCTION

Conventionally, patients with irritable bowel syndrome (IBS) are subgrouped based on their predominant bowel habit. Given the relevance of psychological comorbidity to IBS symptoms, our aim was to explore an alternative approach to subgrouping by incorporating factors beyond stool form and frequency.

METHODS

We collected demographic, symptom, and psychological health data from 1,375 adult subjects in the community who self-identified as having IBS, identifying 2 cohorts meeting either Rome III or Rome IV criteria. In each cohort, we performed latent class analysis, a method of model-based clustering, to identify specific subgroups (clusters). For each cluster, we drew a radar plot and compared these by visual inspection, describing cluster characteristics.

RESULTS

In total, 1,080 individuals met the Rome III criteria for IBS, and 811 met the Rome IV criteria. In both cohorts, a 7-cluster model was the optimum solution, and the characteristics of the clusters were almost identical between Rome III and IV. Four clusters were defined by the pattern of gastrointestinal symptoms (loose stools and urgency or hard stools and bloating), further differentiated by the presence of abdominal pain not relieved by defecation, and by the extent of psychological comorbidity. Two clusters had below-average gastrointestinal symptoms, differentiated by the extent of psychological comorbidity. The final cluster had well-above-average gastrointestinal symptoms and high levels of psychological comorbidity. The proportion of subjects with severe IBS symptom scores, high levels of perceived stress, and high levels of gastrointestinal symptom-specific anxiety was significantly higher in clusters with high psychological comorbidity (P < 0.001).

DISCUSSION

Latent class analysis identified 7 distinct IBS subgroups characterized by varying degrees of gastrointestinal symptoms, extraintestinal symptoms, and psychological comorbidity. Further research is needed to assess whether they might be used to direct treatment.

Symptom Stability in Rome IV vs Rome III Irritable Bowel Syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is a chronic functional bowel disorder, which follows a relapsing and remitting course. Little is known about how evolving definitions of IBS or treatment for the condition affect symptom stability. We conducted a 12-month longitudinal follow-up study of individuals who self-identified as having IBS to examine these issues.

METHODS

We collected demographic, gastrointestinal symptom, mood, and psychological health data at baseline, and gastrointestinal symptom data at 12 months, from adults who self-identified as having IBS, registered with 3 organizations providing services to people with IBS. We applied the Rome III and Rome IV criteria simultaneously at baseline and 12 months and subtyped participants according to predominant stool form or frequency. We examined stability of a diagnosis of IBS, and stability of IBS subtype, for the Rome IV and III criteria separately and examined the effect of commencing new therapy on fluctuation of symptoms.

RESULTS

Of 1,375 individuals recruited at baseline, 784 (57.0%) provided data at 12 months. Of these, 452 met the Rome IV criteria for IBS at baseline, of whom 133 (29.4%) fluctuated to another functional bowel disorder at 12 months. In the remaining 319 (70.6%) who still met the Rome IV criteria for IBS, IBS subtype changed in 101 (31.7%) subjects, with IBS with mixed bowel habit (IBS-M) the least stable. Commencing a new treatment for IBS did not affect symptom stability. Among 631 who met the Rome III criteria at baseline responding at 12 months, 104 (16.5%) fluctuated to another functional bowel disorder. In the 527 (83.5%) who still met the Rome III criteria for IBS, IBS subtype fluctuated in 129 (24.5%), with IBS-M the most stable subtype. Again, commencing a new treatment for IBS did not affect symptom stability.

DISCUSSION

Fluctuation between functional bowel disorders and predominant stool subtype is common in people with IBS and does not appear to be influenced solely by treatment. Rome IV IBS appears less stable than Rome III IBS.

ACG Clinical Guideline: Management of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a highly prevalent, chronic disorder that significantly reduces patients' quality of life. Advances in diagnostic testing and in therapeutic options for patients with IBS led to the development of this first-ever American College of Gastroenterology clinical guideline for the management of IBS using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Twenty-five clinically important questions were assessed after a comprehensive literature search; 9 questions focused on diagnostic testing; 16 questions focused on therapeutic options. Consensus was obtained using a modified Delphi approach, and based on GRADE methodology, we endorse the following: We suggest that a positive diagnostic strategy as compared to a diagnostic strategy of exclusion be used to improve time to initiating appropriate therapy. We suggest that serologic testing be performed to rule out celiac disease in patients with IBS and diarrhea symptoms. We suggest that fecal calprotectin be checked in patients with suspected IBS and diarrhea symptoms to rule out inflammatory bowel disease. We recommend a limited trial of a low fermentable oligosaccharides, disacchardies, monosaccharides, polyols (FODMAP) diet in patients with IBS to improve global symptoms. We recommend the use of chloride channel activators and guanylate cyclase activators to treat global IBS with constipation symptoms. We recommend the use of rifaximin to treat global IBS with diarrhea symptoms. We suggest that gut-directed psychotherapy be used to treat global IBS symptoms. Additional statements and information regarding diagnostic strategies, specific drugs, doses, and duration of therapy can be found in the guideline.

Irritable bowel syndrome

Irritable bowel syndrome is a functional gastrointestinal disorder with symptoms including abdominal pain associated with a change in stool form or frequency. The condition affects between 5% and 10% of otherwise healthy individuals at any one point in time and, in most people, runs a relapsing and remitting course. The best described risk factor is acute enteric infection, but irritable bowel syndrome is also more common in people with psychological comorbidity and in young adult women than in the rest of the general population. The pathophysiology of irritable bowel syndrome is incompletely understood, but it is well established that there is disordered communication between the gut and the brain, leading to motility disturbances, visceral hypersensitivity, and altered CNS processing. Other less reproducible mechanisms might include genetic associations, alterations in gastrointestinal microbiota, and disturbances in mucosal and immune function. In most people, diagnosis can be made on the basis of clinical history with limited and judicious use of investigations, unless alarm symptoms such as weight loss or rectal bleeding are present, or there is a family history of inflammatory bowel disease or coeliac disease. Once the diagnosis is made, an empathetic approach is key and can improve quality of life and symptoms, and reduce health-care expenditure. The mainstays of treatment include patient education about the condition, dietary changes, soluble fibre, and antispasmodic drugs. Other treatments tend to be reserved for people with severe symptoms and include central neuromodulators, intestinal secretagogues, drugs acting on opioid or 5-HT receptors, or minimally absorbed antibiotics (all of which are selected according to predominant bowel habit), as well as psychological therapies. Increased understanding of the pathophysiology of irritable bowel syndrome in the past 10 years has led to a healthy pipeline of novel drugs in development.

Global prevalence of irritable bowel syndrome according to Rome III or IV criteria: a systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common functional bowel disorders, but community prevalence appears to vary widely between different countries. This variation might be due to the fact that previous cross-sectional surveys have neither applied uniform diagnostic criteria nor used identical methodology, rather than being due to true global variability. We aimed to determine the global prevalence of IBS.

METHODS

We did a systematic review and meta-analysis of data from all population-based studies using relatively uniform methodology and using only the most recent iterations of the Rome criteria (Rome III and IV). We searched MEDLINE, Embase, and Embase Classic (from Jan 1, 2006, to April 30, 2020) to identify cross-sectional surveys reporting the prevalence of IBS in adults (≥90% of participants aged ≥18 years) according to the Rome III or Rome IV criteria. We also hand-searched a selection of conference proceedings for relevant abstracts published between 2006 and 2019. We extracted prevalence data for all studies, according to the criteria used to define the presence of IBS. We did a meta-analysis to estimate pooled prevalence rates, according to study location and certain other characteristics (eg, sex and IBS subtype).

FINDINGS

We identified 4143 citations, of which 184 studies appeared relevant. 57 of these studies were eligible, and represented 92 separate adult populations, comprising 423 362 participants. The pooled prevalence of IBS in 53 studies that used the Rome III criteria, from 38 countries and comprising 395 385 participants, was 9·2% (95% CI 7·6-10·8; I²=99·7%). By contrast, pooled IBS prevalence among six studies that used the Rome IV criteria, from 34 countries and comprising 82 476 individuals, was 3·8% (95% CI 3·1-4·5; I²=96·6%). IBS with mixed bowel habit (IBS-M) was the most common subtype with the Rome III criteria, reported by 33·8% (95% CI 27·8-40·0; I²=98·1%) of people fulfilling criteria for IBS (ie, 3·7% [2·6-4·9] of all included participants had IBS-M), but IBS with diarrhoea (IBS-D) was the most common subtype with the Rome IV criteria (reported by 31·5% [95% CI 23·2-40·5; I²=98·1% 61·6%] of people with IBS, corresponding to 1·4% [0·9-1·9] of all included participants having IBS-D). The prevalence of IBS was higher in women than in men (12·0% [95% CI 9·3-15·0] vs 8·6% [6·3-11·2]; odds ratio 1·46 [95% CI 1·33-1·59]). Prevalence varied substantially between individual countries, and this variability persisted even when the same diagnostic criteria were applied and identical methodology was used in studies.

INTERPRETATION

Even when uniform symptom-based criteria are applied, based on identical methodology, to define the presence of IBS, prevalence varies substantially between countries. Prevalence was substantially lower with the Rome IV criteria, suggesting that these more restrictive criteria might be less suitable than Rome III for population-based epidemiological surveys.

FUNDING

None.

Utility of gastrointestinal ultrasound in functional gastrointestinal disorders: A narrative review

Gastrointestinal (GI) ultrasound (GIUS) is valuable in the evaluation of GI diseases such as inflammatory bowel disease, but its use in functional GI disorders (FGIDs) is largely unknown although promising. In order to review the current knowledge on current and potential uses of GIUS in FGIDs, information was obtained via a structured literature search through PubMed, EMBASE and Google Scholar databases with a combination of MESH and keyword search terms: “ultrasound”, “functional GI disorders”, “irritable bowel syndrome”, “functional dyspepsia”, “intestinal ultrasound”, “point of care ultrasonography”, “transabdominal sonography”, “motility”, “faecal loading”, “constipation”. GIUS is currently used for various settings involving upper and lower GI tracts, including excluding organic diseases, evaluating physiology, guiding treatment options and building rapport with patients. GIUS can be potentially used to correlate mechanisms with symptoms, evaluate mechanisms behind treatment efficacy, and investigate further the origin of symptoms in real-time. In conclusion, GIUS is unique in its real-time, interactive and non-invasive nature, with the ability of evaluating several physiological mechanisms with one test, thus making it attractive in the evaluation and management of FGIDs. However, there are still limitations and concerns of operator dependence and lack of validation data for widespread implementation of GIUS in FGIDs.

Relationships of Microbiome Markers With Extraintestinal, Psychological Distress and Gastrointestinal Symptoms, and Quality of Life in Women With Irritable Bowel Syndrome

INTRODUCTION

Altered microbial diversity has been associated with gastrointestinal (GI) symptoms in persons with irritable bowel syndrome (IBS). Less is known about the relationship of microbiome with extraintestinal pain and psychological distress symptoms and quality of life (QOL) in persons with IBS. We aimed to evaluate the relationship of fecal microbiota to GI symptoms, stool consistency, psychological distress, extraintestinal pain, and QOL in participants meeting Rome III criteria for IBS.

METHODS

Seventy-six women completed a 28-day diary that included GI, stool consistency, psychological distress, and extraintestinal pain ratings. Participants completed the IBS-Specific Quality of Life questionnaire. Stool samples were collected and analyzed by 16S rRNA gene sequencing. Principal component analysis was performed and the first 2 components (PC1, PC2) were used to test relationships among bacterial families and clinical measures.

RESULTS

Participants were categorized as IBS constipation (n=22), IBS diarrhea (n=39), IBS mixed (n=13), and IBS unsubtyped (n=2). There was a significant group effect for the Firmicutes to Bacteroidetes ratio and PC1. Lower microbial diversity and richness were associated with increased urgency and extraintestinal pain, worse QOL, and looser stools. Lower extraintestinal pain was associated with increased Rikenellaceae, Christensenellaceae, Dehalobabacteriaceae, Oscillospiraceae, Mogibacteriaceae, Ruminococcaceae, Sutterellaceae, Desulfovibrionaceae, and Erysipelotrichaceae abundances. QOL was positively associated with many of these same bacterial families. Higher Firmicutes to Bacteroidetes ratio was positively associated with loose stools. There were no statistically significant relationships between daily psychological distress or abdominal pain and bacterial families.

CONCLUSIONS

Stool microbial diversity and composition are linked to daily extraintestinal symptoms, stool consistency, and QOL in women with IBS.

Cognitive and Behavioral Differences Between Subtypes in Refractory Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal syndrome consisting of different bowel pattern subtypes: diarrhea predominant (IBS-D), constipation predominant (IBS-C), and alternating (IBS-A). This paper aimed to identify whether (a) psychological factors implicated in the cognitive behavioral model of IBS were differentially associated with bowel pattern subtypes, (b) whether there were differences in symptom severity and work and social adjustment across the IBS-subtypes. Analysis was conducted on baseline data of 557 individuals with refractory IBS recruited into the Assessing Cognitive Therapy in Irritable Bowel (ACTIB) randomized controlled trial. Correlations assessed the associations between psychological factors, stool patterns, symptom severity, and work and social adjustment. Hierarchical regressions identified whether cognitive and behavioral factors were significantly associated with frequency of loose/watery stools, hard/lumpy stools and symptom severity while controlling for affective (anxiety and depression) and demographic factors (age, gender, symptom duration). One-way ANOVAs were conducted to assess differences across Rome III classified subtypes (IBS-A, D and C) in cognitive, behavioral, affective, symptom severity, and adjustment measures. Psychological factors were significantly associated with symptom severity and work and social adjustment. Increased avoidance behavior and unhelpful gastrointestinal (GI) cognitions were significantly associated with higher frequency of loose/watery stools. Increased control behaviors were associated with higher frequency of hard/lumpy stools. Cognitive and behavioral differences were significant across the Rome III classified IBS subtypes. There were no differences in anxiety, depression, overall symptom severity, or work and social adjustment. The results are discussed in terms of their utility in tailoring cognitive behavioral treatments to IBS subtypes.

Chronic functional constipation is strongly linked to vitamin D deficiency

BACKGROUND

Few studies have examined intestinal motility disorders, which are disabling conditions associated with chronic functional constipation, whose pathogenesis is actually not well-defined.

AIM

To investigate the relationship between serum 25-hydroxyvitamin D levels and functional chronic constipation associated to intestinal motility disorders.

METHODS

We performed a prospective case-control study, from May-June to November 2017. Glucose/lactulose breath tests, radiopaque markers (multiple capsule techniques) and wireless motility capsule analysis were used to assess colonic and oro-cecal transit time, after excluding small-intestinal bacterial overgrowth condition. Then, we measured 25-hydroxyvitamin D levels in patients with intestinal motility disorders and we further evaluated the influence of intestinal motility disorders on psychological symptoms/quality of life using validated questionnaires, the Irritable Bowel Syndrome Quality of life (IBS-QOL), the Short Form Health Survey 12, and the Hospital Anxiety and Depression Scale 14 (HADS-14 A and HADS-14 D).

RESULTS

We enrolled 86 patients with chronic functional constipation associated to intestinal motility disorders and 86 matched healthy subjects. Patients with intestinal motility disorders had lower 25-hydroxyvitamin D levels (P < 0.001), and they showed a significant impairment of all health-related quality of life and psychological tests (IBS-QOL, Short Form Health Survey 12-Physical Component Summary, Short Form Health Survey 12-Mental Component Summary, HADS-14 A and HADS-14 D), as compared to the control group (P < 0.001), which significantly correlated with low vitamin D levels (r = - 0.57, P < 0.001; r = 0.21, P = 0.01; r = - 0.48, P < 0.001; r = - 0.57, P < 0.001; r = - 0.29, P < 0.001, respectively). At multivariate analysis vitamin D low levels remained a significant independent risk factor for the occurrence of intestinal motility disorder (odds ratio = 1.19; 95% confidence interval: 1.14-1.26, P < 0.001).

CONCLUSION

Vitamin D deficiency, anxiety and depression symptoms are commonly associated with chronic functional constipation induced by intestinal motility disorders. Vitamin D serum levels should be routinely measured in these patients.

Validity of an observational assessment tool for multifaceted evaluation of faecal condition

Faecal volume, form, colour, and odour are associated with various diseases, dietary habits, and the gut microbiome. Multifaceted assessment of faecal condition will be needed for future research and practice. Faecal observation has advantages, as it is non-invasive, frequent, and easy. We have developed and validated an illustrative card tool for comprehensively faecal assessment. In 38 healthy adults, observations of volume, form, colour, and odour of faeces using the tool were compared to the objective characteristics of the actual faeces determined using a weighing scale, moisture meter, hardness meter, colourimeter, and odour measuring device. A significant positive correlation (ρ = 0.778) was observed between the number of faecal model (2 cm × 10 cm) units and the actual weight. The Bristol Stool Form Scale showed a significant positive correlation with the moisture content (ρ = 0.717) and negative correlations with faecal hardness (ρ = −0.843) and adhesiveness (ρ = −0.761). The L*a*b* colour space values of the stool differed significantly among observational judgments using the colour card tool. No significant correlation was observed between the observation of odour and the measured odour index. In conclusion, the faecal volume, form, and colour can be estimated by observation using the multifaceted assessment card tool.

Bile and fat excretion are biomarkers of clinically significant diarrhoea and constipation in irritable bowel syndrome

BACKGROUND

Biomarkers in irritable bowel syndrome (IBS) may guide targeted therapy in this multifactorial disease. It has been suggested that 75% accuracy and cost <$500 categorise biomarkers as cost-effective.

AIM

To identify differences in faecal bile acids, faecal fat and fasting serum C4 (7a-hydroxy-4-cholesten-3-one) and fibroblast growth factor 19 (FGF19) among patients with IBS-D, IBS-C and healthy controls and to determine accurate, cost-effective biomarkers for clinically relevant diarrhoea and constipation.

METHODS

We assessed daily stool frequency and consistency (Bristol Stool Form Scale) from validated bowel diaries, 48 hours total and individual faecal bile acids, 48 hours faecal fat and weight, fasting serum C4 and FGF19, and colonic transit by scintigraphy from healthy volunteers (HV) and patients with IBS-D and IBS-C (Rome III criteria). We utilised multivariate logistic regression to determine biomarkers of clinically significant diarrhoea or constipation based on stool frequency, consistency and weight.

RESULTS

Among the 126 HV (44M/82F, 37.5 ± 10.9 years [SD]), 64 IBS-D (5M/59F, 41.9 ± 12.2 years), and 30 IBS-C (0M/30F, 44.6 ± 10 years) patients, there were significant differences between all groups in stool weight, frequency, and consistency; in addition, there were differences in colonic transit at 48 hours, faecal fat, and total and individual faecal bile acids between IBS-D and IBS-C. Reduced total and primary faecal bile acids and increased faecal lithocholic acid were significant predictors of decreased faecal weight, frequency and consistency with AUC > 0.82 (sensitivity >76%, specificity >72%). Total and primary faecal bile acids and faecal fat were significant predictors of increased stool weight, frequency and consistency with AUC > 0.71 (sensitivity >55%, specificity >74%).The faecal parameters had a 11.5 positive likelihood ratio in predicting elevated faecal weight.

CONCLUSIONS

Faecal bile acids and faecal fat are cost-effective and accurate biomarkers associated with significant bowel dysfunction among IBS-D and IBS-C patients.

High Rates of Non-Response Across Treatment Attempts in Chronic Irritable Bowel Syndrome: Results From a Follow-Up Study in Tertiary Care

Objective: Despite a wealth of treatment options for irritable bowel syndrome (IBS), data on the subjective experience of treatments in ongoing clinical practice are sparse. This follow-up study assessed the individual usage of treatment modalities by IBS patients over time and investigated the patients' subjective experience of therapeutic impact. Methods: The study was conducted at the Specialty Clinic for Functional Gastrointestinal Disorders of the Heidelberg University Hospital. All patients who fulfilled the Rome III criteria for IBS and treated in our outpatient clinic between January 2012 and December 2016 were invited to the assessment. The primary outcome variables were individual usage of treatment modalities and the Patient Global Impression of Change (PGIC) with treatments. Results: Three hundred and sixty-six patients fulfilled the Rome III criteria for IBS and thus were eligible for this study. Two hundred and seven patients dropped out from the study. The study could include 159 patients (43.7 ± 17.1 years; 71.1% female). The mean time since the first visit to the clinic was 2.8 ± 1.3 years (median 3.0 years). The mean time of symptom duration was 14.1 ± 11.1 years (median 10 years). The average number of treatment attempts was 12, ranging from 2 to 39). With respect to the subjective experience of therapeutic impact, there were no significant differences in the PGIC scores among different treatments (p = 0.183). The rates of non-response rates (minimally improved, no change, or minimally worse) ranged from 63.0% to 83.9%. The PGIC score was correlated negatively with the mean number of treatment attempts (r = -0.316, p < 0.01). The mean number of treatment attempts was correlated negatively with quality of life (r = -0.262, p < 0.01). Conclusion: A multidisciplinary treatment approach of IBS is characterized by high rates of non-response and a high number of frustrating treatment attempts. The connection between the various treatment attempts and the frustrating subjective experience of therapeutic impact puts a substantial burden on IBS patients.

Clinical and psychological correlates of soiling in adult patients with functional gastrointestinal disorders

BACKGROUND/AIMS

Fecal soiling (FS) is the staining of underwear without loss of significant amounts of fecal material. It is frequently associated with defecation disorders in children. The aim of this study was to search for psychological and clinical correlates of adult patients with soiling. Clinically, the complaint of staining is confused with that of fecal incontinence (FI) in the mind of both patients and attending physicians.

DESIGN

Observational study PATIENTS AND METHOD: We included 1454 consecutive outpatients (71% females). They filled out the Rome III questionnaire for functional gastrointestinal disorders (FGIDs); Beck depression inventory, and state and trait anxiety questionnaires; and Likert scales for constipation, diarrhea, bloating, and abdominal pain. Data were analyzed using ANOVA and logistic regression analysis.

RESULTS

Soiling was found in 123 patients (8.5%). They reported similar frequencies of esophageal, gastroduodenal, and abdominal pain as patients without soiling. In contrast, patients with soiling reported higher prevalence of IBS, such as IBS-Diarrhea, Mixed-IBS, functional diarrhea, functional constipation, and levator ani syndrome, and higher Likert scale for diarrhea, bloating, abdominal pain, and softer stools. The multivariable logistic regression analysis shows that patients with soiling have increased odds to report IBS (P = 0.019; OR = 1.958; 95% CI = [1.118-3.431]), functional diarrhea (P = 0.040; OR = 1.901; 95% CI = [1.028-3.513]), and high Diarrhea Likert scale (P < 0.001; OR = 1.215; 95% CI = [1.130-1.306]). No association was found with psychological evaluation.

CONCLUSION

In FGID patients, soiling is not associated with psychological disorders and is mainly associated with IBS and functional diarrhea.

Systemic cytokines are elevated in a subset of patients with irritable bowel syndrome but largely unrelated to symptom characteristics

BACKGROUND

Serum levels of pro-inflammatory cytokines tend to be increased in irritable bowel syndrome (IBS) patients, or subgroups thereof. Still, the link between cytokine levels and IBS symptoms is unclear. We aim to determine systemic cytokine levels in IBS patients and healthy subjects (HS), confirm the presence of a subset of patients with an increased immune activity and to establish if cytokines are linked to IBS symptoms and pathophysiological factors.

METHODS

Serum levels of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF), and IL-10 were measured. All subjects reported IBS symptoms using validated questionnaires and underwent colonic sensorimotor testing. Multivariate supervised orthogonal partial least squares-discriminant analysis (OPLS-DA) and unsupervised principal component analysis (PCA) and hierarchical cluster analysis (HCA) were implemented.

KEY RESULTS

Irritable bowel syndrome patients (n = 246) had higher serum levels of IL-1β, IL-6, IL-8, TNF, and IL-10 compared to HS (n = 21); however, serum cytokine profiles could not discriminate patients from HS. Moreover, cytokine levels were not correlated with symptoms among patients. Supervised OPLS-DA identified 104 patients (40% of patients) and unsupervised HCA analysis identified 49 patients (20%) with an increased immune activity indicated by elevated levels of serum cytokines compared to HS and the other patients. However, irrespective of how patients with increased immune activity were identified they were symptomatically similar to patients with no indication of increased immune activity.

CONCLUSIONS & INFERENCES

Serum cytokines are elevated in IBS patients compared to HS. Immune activation characterizes a subset of patients, but modest associations between cytokine profile and symptoms suggest immune activity does not directly influence symptoms in IBS.

A randomized controlled trial of probiotics for Clostridium difficile infection in adults (PICO)

Background

Clostridium difficile is the most common cause of hospital-acquired infections, responsible for >450000 infections annually in the USA. Probiotics provide a promising, well-tolerated adjunct therapy to standard C. difficile infection (CDI) treatment regimens, but there is a paucity of data regarding their effectiveness for the treatment of an initial CDI.

Objectives

We conducted a pilot randomized controlled trial of 33 participants from February 2013 to February 2015 to determine the feasibility and health outcomes of adjunct probiotic use in patients with an initial mild to moderate CDI.

Methods

The intervention was a 28 day, once-daily course of a four-strain oral probiotic capsule containing Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Bifidobacterium lactis Bi-07 and B. lactis Bl-04. The control placebo was identical in taste and appearance. Registered at clinicaltrials.gov: trial registration number = NCT01680874.

Results

Probiotic adjunct therapy was associated with a significant improvement in diarrhoea outcomes. The primary duration of diarrhoea outcome (0.0 versus 1.0 days; P = 0.039) and two exploratory outcomes, total diarrhoea days (3.5 versus 12.0 days; P = 0.005) and rate of diarrhoea (0.1 versus 0.3 days of diarrhoea/stool diary days submitted; P = 0.009), all decreased in participants with probiotic use compared with placebo. There was no significant difference in the rate of CDI recurrence or functional improvement over time between treatment groups.

Conclusions

Probiotics are a promising adjunct therapy for treatment of an initial CDI and should be further explored in a larger randomized controlled trial.

Gut Microbiota-Based Therapies for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common, heterogeneous disorder characterized by abdominal pain associated with changes in bowel habits. The pathogenesis of IBS is multifactorial and may relate to alterations in the gut microbiota, changes in visceral sensation and motility, and genetic and environmental factors. Administration of systemic antibiotics may increase the risk of IBS by altering gastrointestinal homeostasis. Therapeutic interventions for IBS with diarrhea that are thought to target alterations in the gut microbiota include the nonsystemic antibiotic rifaximin, the medical food serum-derived bovine immunoglobulin, prebiotics, probiotics, and dietary modification. SYN-010 is a modified-release statin formulation that reduces methane production by Methanobrevibacter smithii and is currently in development for the treatment of patients with constipation-predominant IBS. Use of these interventions in the management of patients with IBS may function to restore a healthy gut microbiota and ameliorate symptoms of IBS.

Prediction of Delayed Colonic Transit Using Bristol Stool Form and Stool Frequency in Eastern Constipated Patients: A Difference From the West

Background/Aims

The correlation between the Bristol stool form scale (BSFS) and colonic transit time (CTT) has been reported in Western populations. Our study aims to study the relationship between BSFS, stool frequency, and CTT in Eastern patients with chronic constipation.

Methods

A total of 144 chronic functional constipation patients underwent colonic transit study by using radio-opaque markers, anorectal manometry, and balloon expulsion test. Stool diary including stool forms and frequency was recorded. Delayed CTT was defined as the retention of more than 20.0% of radio-opaque markers in the colon on day 5.

Results

Twenty-five patients (17.4%) had delayed colonic transit. Mean 5-day BSFS (OR, 0.51; 95% CI, 0.34–0.79; P = 0.021) and stool frequency (OR, 0.60; 95% CI, 0.44–0.83; P = 0.002) were independently associated with delayed CTT by logistic regression analysis. Mean 5-day BSFS (area under the curve [AUC], 0.73; 95% CI, 0.62–0.84; P < 0.001) and stool frequency (AUC, 0.75; 95% CI, 0.63–0.87; P < 0.001) fairly predicted delayed CTT. The optimal mean 5-day BSFS of ≤ 3 provided 68.0% sensitivity, 69.7% specificity, and 69.4% accuracy, and the optimal stool frequency ≤ 2 bowel movements in 5 days provided 64.0% sensitivity, 83.1% specificity, and 84.0% accuracy for predicting delayed CTT.

Conclusions

Both stool form and frequency were significantly associated with delayed CTT. Stool frequency ≤ 2 and BSFS 1–3 rather than BSFS 1–2 that was used in the Westerners could be used as surrogate for delayed CTT in Eastern patients with constipation.

Long-term irritable bowel syndrome symptom control with reintroduction of selected FODMAPs

AIM

To investigate the long-term effect of dietary education on a low fermentable oligosaccharide, disaccharide and polyol (FODMAP) diet on irritable bowel syndrome (IBS) symptoms and quality of life (QoL).

METHODS

Participants with IBS (Rome III) were randomized to two groups. Group I commenced a low FODMAP diet at baseline. At three months, group II, so far a comparator group, crossed over to a low FODMAP diet while group I started re-challenging foods. All patients completed the IBS SSS (IBS symptom severity scoring system, 0-500 points increasing with severity), IBS QoL questionnaire (0-100 increasing with QoL), a FODMAP specific food frequency questionnaire and provided a stool sample at baseline, three and six months for microbiome analysis.

RESULTS

Fifty participants were enrolled into group I (n = 23) or group II (n = 27). Participants in both groups were similar in baseline values but with more men in group I. There was a significantly lower IBS SSS (275.6 ± 63.6 to 128.8 ± 82.5 vs 246.8 ± 71.1 to 203.6 ± 70.1) (P < 0.0002) and increased QoL (68.5 ± 18.0 to 83 ± 13.4 vs 72.9 ± 12.8 to 73.3 ± 14.4) (P < 0.0001) in group I vs group II at 3 mo. The reduced IBS SSS was sustained at 6 mo in group I (160 ± 102) and replicated in group II (124 ± 76). Fiber intake decreased on the low FODMAP diet (33 ± 17 g/d to 21 ± 8 g/d) (P < 0.01) and after re-introducing FODMAP containing foods increased again to 27 ± 9 g/d. There was no change seen in the intestinal microbiome when participants adopted a low FODMAP diet.

CONCLUSION

This study demonstrated that a reduction in FODMAPs improves symptoms in IBS and this improvement can be maintained while reintroducing FODMAPs.

Update on Rome IV Criteria for Colorectal Disorders: Implications for Clinical Practice

PURPOSE OF REVIEW

The purpose of the review was to provide an update of the Rome IV criteria for colorectal disorders with implications for clinical practice.

RECENT FINDINGS

The Rome diagnostic criteria are expert consensus criteria for diagnosing functional gastrointestinal disorders (FGIDs). The current version, Rome IV, was released in May of 2016 after Rome III had been in effect for a decade. It is the collective product of committees that included more than 100 leading functional GI experts. For functional bowel and anorectal disorders, the majority of changes relative to Rome III are relatively minor and will have little impact on clinical practice. However, notable changes with potential impact on clinical practice and research include the changes in the diagnostic criteria for IBS, the modified approach for subtyping of IBS, the view on functional bowel disorders as a spectrum of disorders, and the new definition of fecal incontinence. New features in the Rome IV diagnostic criteria for functional bowel and anorectal disorders will likely have modest influence on clinical practice, with a few exceptions.

Derivation and validation of a diagnostic test for irritable bowel syndrome using latent class analysis

BACKGROUND

The accuracy of symptom-based diagnostic criteria for irritable bowel syndrome (IBS) is modest.

AIMS

To derive and validate a new test that utilises latent class analysis.

METHODS

Symptom, colonoscopy, and histology data were collected from 1981 patients and 360 patients in two cohorts referred to secondary care for investigation of their gastrointestinal symptoms in Canada and the UK, respectively. Latent class analysis was used to identify naturally occurring clusters in patient-reported symptoms in the Canadian dataset, and the latent class model derived from this was then applied to the UK dataset in order to validate it. Sensitivity, specificity, and positive and negative likelihood ratios (LRs) were calculated for the latent class models.

RESULTS

In the Canadian cohort, the model had a sensitivity of 44.7% (95% CI 40.0-50.0) and a specificity of 85.3% (95% CI 83.4-87.0). Positive and negative LRs were 3.03 (95% CI 2.57-3.56) and 0.65 (95% CI 0.59-0.71) respectively. A maximum positive LR of 3.93 was achieved following construction of a receiver operating characteristic curve. The performance in the UK cohort was similar, with a sensitivity and specificity of 52.5% (95% CI 42.2-62.7) and 84.3% (95% CI 79.3-88.6), respectively. Positive and negative LRs were 3.35 (95% CI 2.38-4.70) and 0.56 (95% CI 0.45-0.68), respectively, with a maximum positive LR of 4.15.

CONCLUSIONS

A diagnostic test for IBS, utilising patient-reported symptoms incorporated into a latent class model, performs as accurately as symptom-based criteria. It has potential for improvement via addition of clinical markers, such as coeliac serology and faecal calprotectin.

Distinct Abnormalities of Small Bowel and Regional Colonic Volumes in Subtypes of Irritable Bowel Syndrome Revealed by MRI

OBJECTIVES

Non-invasive biomarkers which identify different mechanisms of disease in subgroups of irritable bowel syndrome (IBS) could be valuable. Our aim was to seek useful magnetic resonance imaging (MRI) parameters that could distinguish each IBS subtypes.

METHODS

34 healthy volunteers (HV), 30 IBS with diarrhea (IBS-D), 16 IBS with constipation (IBS-C), and 11 IBS with mixed bowel habit (IBS-M) underwent whole-gut transit and small and large bowel volumes assessment with MRI scans from t=0 to t=360 min. Since the bowel frequency for IBS-M were similar to IBS-D, IBS-M and IBS-D were grouped together and labeled as IBS non-constipation group (IBS-nonC).

RESULTS

Median (interquartile range): fasting small bowel water content in IBS-nonC was 21 (10-42), significantly less than HV at 44 ml (15-70), P<0.01 as was the postprandial area under the curve (AUC) P<0.01. The fasting transverse colon volumes in IBS-C were significantly larger at 253 (200-329) compared with HV, IBS-nonC whose values were 165 (117-255) and 198 (106-270) ml, respectively, P=0.02. Whole-gut transit time for IBS-C was prolonged at 69 (51-111), compared with HV at 34 (4-63) and IBS-D at 34 (17-78) h, P=0.03. Bloating score (VAS 0-10 cm) correlated with transverse colon volume at t=405 min, Spearman r=0.21, P=0.04.

CONCLUSIONS

The constricted small bowel in IBS-nonC and the dilated transverse colon in IBS-C point to significant differences in underlying mechanisms of disease.

Is-it possible to distinguish irritable bowel syndrome with constipation from functional constipation?

BACKGROUND

The Rome III criteria classify patients complaining of constipation into two main groups: patients with functional constipation (FC) and patients with constipation predominant irritable bowel syndrome (IBS-C). The purpose of this study was to identify differences in the intensity of symptoms and total and segmental colonic transit time in these two types of patients.

METHODS

We performed a prospective evaluation of 337 outpatients consecutively referred for chronic constipation and classified according to the Rome III criteria as FC or IBS-C. They were asked to report symptom intensity, on a 10-point Likert scale, for diarrhea, constipation, bloating and abdominal pain. Stool form was reported using the Bristol scale, and colonic transit time was measured by using multiple-ingestion single-marker single-film technique. Statistical analysis was completed by a discriminant analysis.

RESULTS

Female gender and obstructed defecation was more frequent in IBS-C patients than in FC patients. IBS-C patients reported greater symptom intensity than FC patients, but stool form, and total and segmental colonic transit time were not different between the two groups. Multivariate logistic regression showed that only two parameters, bloating and abdominal pain, were related to the IBS-C or to the FC phenotype, and discriminant analysis showed that these two parameters were sufficient to give a correct classification of 71% of the patients.

CONCLUSIONS

Our study suggests that self-evaluation of abdominal pain and bloating is more helpful than colonic transit time in classifying patient as IBS-C or FC.

A mechanistic multicentre, parallel group, randomised placebo-controlled trial of mesalazine for the treatment of IBS with diarrhoea (IBS-D)

INTRODUCTION

Immune activation has been reported in the mucosa of IBS patients with diarrhoea (IBS-D), and some small studies have suggested that mesalazine may reduce symptoms. We performed a double-blind, randomised placebo-controlled trial of 2 g mesalazine twice daily versus placebo for 3 months in patients with Rome III criteria IBS-D. Primary outcome was daily average stool frequency during weeks 11-12; secondary outcomes were abdominal pain, stool consistency, urgency and satisfactory relief of IBS symptoms.

METHODS

Participants were randomised after a 2-week baseline stool diary. All participants completed a 12-week stool diary and at the end of each week recorded the presence of 'satisfactory relief of IBS symptoms'.

RESULTS

136 patients with IBS-D (82 women, 54 men) were randomised, 10 patients withdrew from each group. Analysis by intention to treat showed the daily average stool frequency during weeks 11 and 12 were mean (SD), 2.8 (1.2) in mesalazine and 2.7 (1.9) in the placebo group with no significant group difference, (95% CI) 0.1 (-0.33 to 0.53), p=0.66. Mesalazine did not improve abdominal pain, stool consistency nor percentage with satisfactory relief compared with placebo during the last two-weeks follow-up.

CONCLUSIONS

This study does not support any clinically meaningful benefit or harm of mesalazine compared with placebo in unselected patients with IBS-D. More precise subtyping based on underlying disease mechanisms is needed to allow more effective targeting of treatment in IBS.

TRIAL REGISTRATION NUMBER

NCT01316718.

Symptom Profiles in Patients With Irritable Bowel Syndrome or Functional Abdominal Pain Compared With Healthy Controls

OBJECTIVES

Patient-reported outcome (PRO) measures of gastrointestinal symptoms are recommended to determine treatment effects for irritable bowel syndrome (IBS) and functional abdominal pain (FAP). Study objectives were to compare the symptom profiles of pediatric patients with IBS or FAP with healthy controls and with each other using the PedsQL Gastrointestinal Symptoms and Gastrointestinal Worry Scales, and to establish clinical interpretability of PRO scale scores through identification of minimal important difference (MID) scores.

METHODS

Gastrointestinal Symptoms and Worry Scales were completed in a 9-site study by 154 pediatric patients and 161 parents (162 families; IBS n = 46, FAP n = 119). Gastrointestinal Symptoms Scales measuring stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea were administered along with Gastrointestinal Worry Scales. A matched sample of 447 families with healthy children completed the scales.

RESULTS

Gastrointestinal Symptoms and Worry Scales distinguished between patients with IBS or FAP compared with healthy controls (P < 0.001), with larger effect sizes (>1.50) for symptoms indicative of IBS or FAP, demonstrating a broad multidimensional gastrointestinal symptom profile and clinical interpretability with MID scores for individual PRO scales. Patients with IBS manifested more symptoms of constipation, gas and bloating, and diarrhea than patients with FAP.

CONCLUSIONS

Patients with IBS or FAP manifested a broad gastrointestinal symptom profile compared with healthy controls with large differences, indicating the critical need for more effective interventions to bring patient functioning within the range of healthy functioning.

Agreement between prospective diary data and retrospective questionnaire report of abdominal pain and stooling symptoms in children with irritable bowel syndrome

BACKGROUND

In functional gastrointestinal disorders, patient recall of symptoms drives diagnostic decisions and evaluation of treatment response, and research conclusions about potential treatments. In pediatrics, parent report also impacts assessment and care. Hence, identifying methods for accurately capturing patient and parent report of irritable bowel syndrome (IBS) symptoms is important. This study evaluated correspondence between retrospective questionnaire (parent and child report) and prospective diary data for children and adolescents with IBS.

METHODS

Participants included 50 children/adolescents with IBS per Rome III criteria. Children completed a 2-week pain and stool diary. Children and parents subsequently completed a 2-week recall questionnaire, reporting number of pain days, maximum pain, days without bowel movement, and days with diarrhea during the diary interval. Intraclass correlation coefficients and Bland-Altman plots assessed agreement.

KEY RESULTS

For pain and days without bowel movement, overall agreement between child recall questionnaire and child diary was strong, although under conditions likely to facilitate agreement and with individual variation observed. Parent recall and child diary were less concordant, and agreement about diarrhea was poor for parent and child. Age did not significantly correlate with agreement.

CONCLUSIONS & INFERENCES

Child questionnaire with short recall interval may be a reasonable approximation for diary data, although this varies by individual and replication/investigation of lengthier recall are needed. Relying on parent questionnaire does not appear a suitable proxy, and recall of stool form by both parent and child appears more problematic. These results combined with existing literature support use of diary data whenever possible.

A meta-analysis of immunogenetic Case-Control Association Studies in irritable bowel syndrome

BACKGROUND

To date, genetic-association studies of single nucleotide polymorphisms (SNP) in selected candidate genes with the symptom phenotype of irritable bowel syndrome (IBS) have typically involved hundreds to 2000 patients. SNPs in immune-related genes, such as cytokine and cytokine receptor encoding genes, have been reported to associate with IBS risk.

METHODS

We conducted two independent case-control studies on 16 SNPs in IL1R1, IL4, IL6, IL8, IL10, IL23R, TNFA, and TNFSF15, one from the UK (194 patients and 92 healthy volunteers) and one from the USA (137 patients and 96 healthy volunteers). The main aim was to examine the relationship between inherited immunological diversity and IBS risk in a meta-analysis which included 12 additional, earlier studies. The meta-analysis comprised a total of 2894 patients (839 IBS-C, 1073 IBS-D, 502 IBS-M), and 3138 healthy volunteers with self-reported Caucasian ancestry.

KEY RESULTS

The association of SNP rs4263839 (TNFSF15) was investigated in four studies and confirmed in the meta-analysis: IBS (OR 1.19, 95% CI 1.08-1.31), and IBS-C (OR 1.24, 95% CI 1.08-1.42). No additional SNPs residing in immunogenes associated with IBS symptom phenotypes.

CONCLUSIONS & INFERENCES

Our meta-analysis could not confirm a major role of most investigated SNPs, but a moderate association between rs4263839 TNFSF15 and IBS, in particular IBS-C. The analysis emphasizes the importance of definition and phenotype homogeneity, adequate study size and representativeness of the patient and control collective.