Patient-reported outcomes for irritable bowel syndrome are associated with patients' severity ratings of gastrointestinal symptoms and psychological factors

Somatization Mediates the Relationship Between Childhood Trauma and Pain Ratings in Patients with Irritable Bowel Syndrome

GOALS

To identify potential mechanisms by which childhood trauma may lead to the adult development of abdominal symptoms in patients with irritable bowel syndrome (IBS).

BACKGROUND

Patients with IBS frequently report a history of childhood trauma. The pathophysiology by which abdominal pain arises in patients with IBS is multidimensional, consisting of both peripheral factors, such as altered motility, inflammation, and bacterial overgrowth, as well as central factors, such as psychological distress and neuro-hormonal dysregulation.

STUDY

Adult psychological factors (anxiety, depression, and somatization) were examined to determine if they mediate the relationship between retrospective reports of childhood trauma and current adult IBS abdominal symptoms in a study of 436 patients (M age=41.6, 79% F) meeting Rome III diagnosis criteria. Childhood trauma was measured using retrospective questions assessing physical and sexual abuse. Psychological factors in adulthood were measured with the subscales of the Brief Symptom Inventory-18. Outcome variables included adult IBS symptoms of abdominal pain, bloating, and satisfaction with bowel habits from the IBS Symptoms Severity Scale.

RESULTS

Results indicated that somatization mediated the relationship between childhood abuse and abdominal pain and bloating but not bowel satisfaction.

CONCLUSIONS

This study provides insight into the multifactorial nature of IBS-associated abdominal pain in patients with a history of childhood trauma, elucidating the need for a trauma-informed treatment approach for patients with histories of abuse.

GI factors, potential to predict prostate motion during radiotherapy; a scoping review

Purpose

A scoping literature review was conducted to identify gastrointestinal (GI) factors most likely to influence prostate motion during radiotherapy. We proffer that patient specific measurement of these GI factors could predict motion uncertainty during radiotherapy, facilitating personalised care by optimising treatment technique e.g., daily adaption or via bespoke patient pre-habilitation and preparation.

Methods

The scoping review was undertaken as per JBI guidelines. Searches were conducted across four databases: Ovid Medline®, EMBASE, CINAHL and EBSCO discovery. Articles written in English from 2010-present were included. Those pertaining to paediatrics, biological women exclusively, infectious and post-treatment GI morbidity and diet were excluded.Common GI factors impacting men were identified and related symptoms, incidence and measurement tools examined. Prevalence among persons with prostate cancer was explored and suitable assessment tools discussed.

Results

A preliminary search identified four prominent GI-factors: mental health, co-morbidity and medication, physical activity, and pelvic floor disorder. The scoping search found 3644 articles; 1646 were removed as duplicates. A further 1249 were excluded after title and abstract screening, 162 remained subsequent to full text review: 42 mental health, 53 co-morbidity and medication, 39 physical activity and 28 pelvic floor disorder.Six GI factors prevalent in the prostate cancer population and estimated most likely to influence prostate motion were identified: depression, anxiety, diabetes, obesity, low physical activity, and pelvic floor disorder. Reliable, quick, and easy to use tools are available to quantify these factors.

Conclusion

A comprehensive GI factor assessment package suitable to implement into the radiotherapy clinic has been created. Unveiling these GI factors upfront will guide improved personalisation of radiotherapy.

Efficacy of a Synbiotic Containing Lactobacillus paracasei DKGF1 and Opuntia humifusa in Elderly Patients with Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial

Background/Aims

There is increasing evidence that supplementation with pre- and probiotics appears to have positive effects on irritable bowel syndrome (IBS). The aim of this study was to determine the effects of a new synbiotic formulation on gastrointestinal symptoms in elderly patients with IBS.

Methods

Sixty-seven IBS patients aged ≥60 years were randomly assigned to either a placebo group (n=34) or a synbiotic group (n=33). During a 4-week intervention, subjects used a placebo or a synbiotic containing Lactobacillus paracasei DKGF1 and extracts of Opuntia humifusa once a day. Patients were evaluated with the subject global assessment, visual analog scale, and Bristol stool chart. The primary outcome was the overall responder rate and the secondary outcome was the responder rates for abdominal symptom reduction at week 4.

Results

Overall, responder rates were significantly higher in the synbiotic group (51.5%) than in the placebo group (23.5%) (p=0.017). Abdominal pain (58.8% vs 81.8%) and psychological well-being (26.4% vs 60.6%) were noticeably improved in the synbiotic group (p=0.038 and p=0.004, respectively). However, there were no significant differences in gas and bloating symptoms (p=0.88 and p=0.88, respectively). In patients with constipation-dominant and diarrhea-dominant IBS (n=16), the synbiotic significantly improved abdominal pain and defecation symptoms (responder rates for the placebo vs the synbiotic: 22.2% vs 85.7%, p=0.04). There were no adverse events in either group.

Conclusions

The results indicate that this new synbiotic supplement can potentially relieve abdominal symptoms in elderly IBS patients.

Linaclotide for treating patients with irritable bowel syndrome with predominant constipation: a multicentre study of real-world data in China

INTRODUCTION

Linaclotide, a guanylate cyclase C agonist that improves the symptoms of irritable bowel syndrome with predominant constipation (IBS-C), has been recently approved for IBS-C treatment. This study aimed to report real-world data on linaclotide treatment in China.

METHODS

This was a prospective multicentre study of the effectiveness of linaclotide treatment in patients with IBS-C from 10 primary medical institutions. Changes in defecation, abdominal symptoms, the IBS symptom severity scale (IBS-SSS), IBS quality of life questionnaire (IBS-QOL), Zung Self-Rating Anxiety Scale and Self-Rating Depression Scale in patients were evaluated to determine the drug's clinical efficacy and safety.

RESULTS

We enrolled 97 patients (mean age: 52.39 ± 13.99 years), 55 of whom were women (56.7%). In terms of efficacy, the number of the patients' defecation per week and Bristol stool form scale scores significantly increased at week 4 and week 12 compared with the values at the baseline. The baseline average IBS-SSS score was 211.01 ± 81.23. Of the patients, 24 had severe IBS-C, and their IBS-SSS scores at week 4 (51.81 ± 54.42) and week 12 (9.3 ± 30.39) significantly decreased and showed a pronounced improvement. The IBS-QOL total scores at week 4 and week 12 gradually decreased compared with that at the baseline and the QOL significantly improved. Treatment satisfaction rate was 79.3% in week 4 and 100% in week 12, showing a gradually increased satisfaction and significant differences. However, 11 cases (11.3%) had diarrhoea.

CONCLUSION

Linaclotide has proved to be a safe and effective drug to improve IBS-C symptoms and severity.

Altered Structural Covariance of Insula, Cerebellum and Prefrontal Cortex Is Associated with Somatic Symptom Levels in Irritable Bowel Syndrome (IBS)

Somatization, defined as the presence of multiple somatic symptoms, frequently occurs in irritable bowel syndrome (IBS) and may constitute the clinical manifestation of a neurobiological sensitization process. Brain imaging data was acquired with T1 weighted 3 tesla MRI, and gray matter morphometry were analyzed using FreeSurfer. We investigated differences in networks of structural covariance, based on graph analysis, between regional gray matter volumes in IBS-related brain regions between IBS patients with high and low somatization levels, and compared them to healthy controls (HCs). When comparing IBS low somatization (N = 31), IBS high somatization (N = 35), and HCs (N = 31), we found: (1) higher centrality and neighbourhood connectivity of prefrontal cortex subregions in IBS high somatization compared to healthy controls; (2) higher centrality of left cerebellum in IBS low somatization compared to both IBS high somatization and healthy controls; (3) higher centrality of the anterior insula in healthy controls compared to both IBS groups, and in IBS low compared to IBS high somatization. The altered structural covariance of prefrontal cortex and anterior insula in IBS high somatization implicates that prefrontal processes may be more important than insular in the neurobiological sensitization process associated with IBS high somatization.

Minimal-Contact Versus Standard Cognitive Behavioral Therapy for Irritable Bowel Syndrome: Cost-Effectiveness Results of a Multisite Trial

BACKGROUND

Irritable bowel syndrome (IBS) is a common, often disabling gastrointestinal (GI) disorder for which there is no satisfactory medical treatment but is responsive to cognitive behavior therapy (CBT).

PURPOSE

To evaluate the costs and cost-effectiveness of a minimal contact version of CBT (MC-CBT) condition for N = 145 for IBS relative to a standard, clinic-based CBT (S-CBT; N = 146) and a nonspecific comparator emphasizing education/support (EDU; N = 145).

METHOD

We estimated the per-patient cost of each treatment condition using an activity-based costing approach that allowed us to identify and estimate costs for specific components of each intervention as well as the overall total costs. Using simple means analysis and multiple regression models, we estimated the incremental effectiveness of MC-CBT relative to S-CBT and EDU. We then evaluated the cost-effectiveness of MC-CBT relative to these alternatives for selected outcomes at immediate posttreatment and 6 months posttreatment, using both an intent-to-treatment and per-protocol methodology. Key outcomes included scores on the Clinical Global Impressions-Improvement Scale and the percentage of patients who positively responded to treatment.

RESULTS

The average per-patient cost of delivering MC-CBT was $348, which was significantly less than the cost of S-CBT ($644) and EDU ($457) (p < .01). Furthermore, MC-CBT produced better average patient outcomes at immediate and 6 months posttreatment relative to S-CBT and EDU (p < .01). The current findings indicated that MC-CBT is a cost-effective option relative to S-CBT and EDU.

CONCLUSION

As predicted, MC-CBT was delivered at a lower cost per patient than S-CBT and performed better over time on the primary outcome of global IBS symptom improvement.

Decline of anterior cingulate functional network efficiency in first-episode, medication-naïve somatic symptom disorder and its relationship with catastrophizing

The high prevalence of somatic symptom disorder (SSD) led to cumulative burdens to the medical system. However, the pathogenesis of this disease still remains unclear. Graph theoretical analysis discovered altered network topology across various psychiatric disorders, yet alteration in the topological structure of brain functional network in SSD patients is still unexplored. Catastrophizing is a common cognitive distortion in SSD. We hypothesize that the network topological metrics of SSD should be altered, and should correlate with catastrophizing scales. 32 medication-naïve, first-episode SSD patients and 30 age, gender matched HCs were recruited. The 17-item Hamilton Depression Rating Scale (HAMD-17), Hamilton Anxiety Rating Scale (HAMA) and Cognitive Emotion Regulation Questionnaire (CERQ) were accessed. Functional MRI were scanned and brain functional networks were constructed based on 166 anatomically cerebrum regions from the automated anatomical labeling 3 (AAL3) template. Network topological metrics were calculated and compared between the two groups. Correlation between these metrics and clinical scales were also calculated. Network global efficiency of SSD was significantly lower than that of HC. Nodal global efficiency of the left subgenual anterior cingulate cortex (sgACC) of SSD was significantly lower than that of HC. FCs between the left sgACC and other 21 seed nodes were significantly declined in SSD in comparison with HC. In SSD group, HAMD total score was significantly negatively correlated with the connection between the left medial superior frontal gyrus and the left sgACC. CERQ catastrophizing score was significantly negatively correlated with nodal global efficiency of left sgACC and with the FCs between the left sgACC and other 13 seed nodes. Catastrophizing could reflect the specific sgACC-centered dysfunction of brain network global efficiency of SSD. The left sgACC may be a future treatment target of dealing with catastrophizing, which is a core cognitive distortion of SSD.

Increasing Rates of Opioid Prescriptions for Gastrointestinal Diseases in the United States

INTRODUCTION

Pain control is an important management approach for many gastrointestinal conditions. Because of the ongoing opioid crisis, public health efforts have focused on limiting opioid prescriptions. This study examines national opioid prescribing patterns and factors associated with opioid prescriptions for gastrointestinal conditions.

METHODS

We conducted a repeated cross-sectional study using the National Ambulatory Medical Care Survey data from 2006 to 2016. The International Classification of Diseases codes were used to identify ambulatory visits with a primary gastrointestinal diagnosis. Data were weighted to calculate national estimates for opioid prescriptions for gastrointestinal disease. Joinpoint regression was used to analyze temporal trends. Multivariable logistic regression was used to examine factors associated with opioid prescriptions.

RESULTS

We analyzed 12,170 visits with a primary gastrointestinal diagnosis, representing 351 million visits. The opioid prescription rate for gastrointestinal visits was 10.1% (95% confidence interval [CI] 9.0%-11.2%). Opioid prescription rates for gastrointestinal disease increased by 0.5% per year from 2006 to 2016 (P = 0.04). Prescription rates were highest for chronic pancreatitis (25.1%) and chronic liver disease (13.9%) visits. Seventy-one percent of opioid prescriptions were continuations of an existing prescription. Patient characteristics associated with continued opioid prescriptions included rural location (adjusted odds ratio [aOR] 1.46; 95% CI 1.11-1.93), depression (aOR 1.83; 95% CI 1.33-2.53), and Medicaid insurance (aOR 1.57; 95% CI 1.15-2.13).

DISCUSSION

Opioid prescription rates for gastrointestinal disease visits increased from 2006 to 2016. Our findings suggest an inadequate response to the opioid epidemic by providers managing gastrointestinal conditions. Further clinical interventions are needed to limit opioid use for gastrointestinal disease.(Equation is included in full-text article.).

Impact of symptom severity in patients with diarrhoea-predominant irritable bowel syndrome (IBS-D): results from two separate surveys of HCPs and patients with IBS-D

BACKGROUND

Management of diarrhoea-predominant irritable bowel syndrome (IBS-D) is generally based on patient-reported symptoms; however, limited information on symptom severity exists. The objective of the study was to assess the impact of IBS-D severity on patient burden and patient and healthcare professional attitudes towards IBS.

METHODS

We conducted two web-based surveys of healthcare professionals and patients from Australia, Canada and Europe. We analysed patient characteristics and attitudes by IBS-D severity, which was assessed retrospectively using a composite of four variables: worst abdominal pain, IBS symptom frequency, Bristol Stool Form Scale and quality of life.

RESULTS

Of 679 healthcare professional respondents, one-third routinely classified patients by severity. The patient survey was completed by 513 patients with mild (26%), moderate (33%) and severe (41%) IBS-D, classified using the composite scale. Age, sex and treatment satisfaction did not change with severity; however, 19% of patients classified with severe IBS-D agreed with the statement: 'When my IBS is bad, I wish I was dead' versus 4 and 7% of patients with mild and moderate IBS-D, respectively (p < 0.05). Significantly more patients classified with severe IBS-D reported medication use versus mild IBS-D.

CONCLUSION

Compared with milder symptoms, severe IBS-D was associated with increased medication use and a negative perspective of IBS-D. This highlights the need for a validated severity scale to inform treatment decisions.

Presentation and Characteristics of Abdominal Pain Vary by Irritable Bowel Syndrome Subtype: Results of a Nationwide Population-Based Study

INTRODUCTION

Abdominal pain is a cardinal feature of irritable bowel syndrome (IBS); however, differences in abdominal pain among IBS subtypes remain unknown. We aimed to characterize abdominal pain symptoms among established IBS subtypes using data from the National Gastrointestinal (GI) Survey.

METHODS

Individuals participating in the National GI Survey completed National Institutes of Health GI Patient-Reported Outcomes Measurement Information System (GI-PROMIS) questionnaires. Adults meeting modified Rome III IBS criteria and reporting abdominal pain in the previous 7 days were eligible. Outcomes included abdominal pain severity, bothersomeness, interference with daily activities, frequency, and location. Results were stratified by subtype (diarrhea [IBS-D], constipation [IBS-C], and mixed [IBS-M]). Regression models adjusted for demographics and comorbidities.

RESULTS

One thousand one hundred fifty-eight individuals (245 IBS-D, 232 IBS-C, and 681 IBS-M) with active IBS symptoms (defined as abdominal pain in the past 7 days) were included. Demographics were similar among the subtypes except for age, race/ethnicity, education, and marital status. The GI-PROMIS score was lower for IBS-D (percentile score of 68.6, SD = 25.1; P = 0.001) and IBS-M (69.1, SD = 25.1; P < 0.001) compared with IBS-C (75.5, SD = 20.7). Abdominal pain was more bothersome (P = 0.001), caused more interference with daily activities (P = 0.03), and was more frequent (P = 0.047) for individuals with IBS-C compared with individuals with IBS-D. No differences in these domains were seen between individuals with IBS-D and IBS-M. Individuals with IBS-C and IBS-M had more widespread pain compared with those with IBS-D.

DISCUSSION

In this population-based study, we found that abdominal pain characteristics differ between the IBS subtypes. Namely, individuals with IBS-C experience more bothersome, frequent, and diffuse abdominal pain compared with those with IBS-D.

Durability and Decay of Treatment Benefit of Cognitive Behavioral Therapy for Irritable Bowel Syndrome: 12-Month Follow-Up

BACKGROUND

There is a need for safe and effective IBS treatments that provide immediate and sustained improvement of IBS symptoms, particularly among more severe patients. The aim was to assess long-term clinical response of cognitive behavioral therapy (CBT) with reference to IBS education.

METHODS

A total of 436 Rome III-diagnosed IBS patients (80% F, M age = 41 years) were randomized to: 4 session home-based CBT (minimal contact (MC-CBT)), 10 session clinic-based CBT (standard (S-CBT)), or 4 session IBS education (EDU). Follow-up occurred at 2 weeks and 3, 6, 9, and 12 months following treatment completion. Treatment response was based a priori on the Clinical Global Improvement Scale (global IBS symptom improvement) and IBS Symptom Severity Scale (IBS-SSS).

RESULTS

Post-treatment CGI gains were generally maintained by MC-CBT patients at quarterly intervals through 12-month follow-up with negligible decay. For MC-CBT and S-CBT, 39 and 33% of respondents maintained treatment response at every follow-up assessment. The corresponding percent for EDU was 19%, which was significantly lower (p < 0.05) than for the CBT groups. On the IBS-SSS, therapeutic gains also showed a pattern of maintenance with trends towards increased efficacy over time in all conditions, with the mean unit reductions between baseline and follows-up being approximately -76 at immediate and approximately -94 at 12 months (-50 = clinically significant).

CONCLUSIONS

For treatment-refractory IBS patients, home- and clinic-based CBT resulted in substantial and enduring relief of multiple IBS symptoms that generally extended to 12-month post treatment.

Gastrointestinal symptom improvement from fiber, STW 5, peppermint oil, and probiotics use-Results from an online survey

OBJECTIVES

Several common supplements are used by a significant number of patients affected by gastrointestinal (GI) disorders to improve symptoms and quality of life. We investigated the impact of GI symptom improvement with the use of fiber, STW 5, probiotics, and peppermint oil in relation to overall GI pain and quality of life via an online survey.

DESIGN

We used a cross-sectional, descriptive, correlation design. A Qualtrics online survey was utilized to collect data from January to June 2013 through various websites. Areas evaluated included participant demographics, use of supplements, and gastrointestinal symptom severity.

RESULTS

The rate of supplement use among patients with GI disorders was high (90% in past year) and consultation with healthcare providers was reported by 80%. Participants who completed the survey (n = 68) reported a strong correlation between GI symptom severity and overall quality of life (r2 = 0.8682, p < 0.001). The use of fiber improved GI symptom severity while both STW 5 and probiotics were linked to specific improvements.

CONCLUSIONS

Persons with chronic GI disorders often choose the complementary use of common supplements to mitigate GI symptoms and consult with their healthcare providers frequently. The use of STW 5 and probiotics specifically is linked to overall reduction in GI symptoms and improvement of quality of life.

UK clinical experience up to 52 weeks with linaclotide for irritable bowel syndrome with constipation

BACKGROUND

Linaclotide, a guanylate cyclase C agonist, has been shown in clinical trials to improve symptoms of irritable bowel syndrome with constipation (IBS-C). Here we report data from a real-world study of linaclotide in the UK.

METHODS

This 1-year, multicentre, prospective, observational study in the UK enrolled patients aged 18 years and over initiating linaclotide for IBS-C. The primary assessment was change from baseline in IBS Symptom Severity Scale (IBS-SSS) score at 12 weeks, assessed in patients with paired baseline and 12-week data. Change from baseline in IBS-SSS score at 52 weeks was a secondary assessment. Adverse events were recorded.

RESULTS

In total, 202 patients were enrolled: 185 (91.6%) were female, median age was 44.9 years (range 18.1-77.2) and 84 (41.6%) reported baseline laxative use. Mean (standard deviation) baseline IBS-SSS score was 339 (92), with most patients (n = 129; 66.8%) classified as having severe disease (score ⩾300). In patients with paired data, there was a significant mean (95% confidence interval) decrease in IBS-SSS score from baseline to 12 weeks [-77.0 (-96.3, -57.7); p < 0.001; n = 124] and baseline to 52 weeks [-70.7 (-95.0, -46.5); p < 0.001; n = 76]. Overall, 174 adverse events were reported in 77 (38.1%) patients, most commonly diarrhoea (n = 54; 26.7%), abdominal pain (n = 21; 10.4%) and abdominal distension (n = 13; 6.4%).

CONCLUSION

Linaclotide significantly improved IBS-SSS score at 12 and 52 weeks. These results provide insights into outcomes with linaclotide treatment over 1 year in patients with IBS-C in real-world clinical practice.

Improvement in Gastrointestinal Symptoms After Cognitive Behavior Therapy for Refractory Irritable Bowel Syndrome

BACKGROUND & AIMS

There is an urgent need for safe treatments for irritable bowel syndrome (IBS) that relieve treatment-refractory symptoms and their societal and economic burden. Cognitive behavior therapy (CBT) is an effective treatment that has not been broadly adopted into routine clinical practice. We performed a randomized controlled trial to assess clinical responses to home-based CBT compared with clinic-based CBT and patient education.

METHODS

We performed a prospective study of 436 patients with IBS, based on Rome III criteria, at 2 tertiary centers from August 23, 2010, through October 21, 2016. Subjects (41.4 ± 14.8 years old; 80% women) were randomly assigned to groups that received the following: standard-CBT (S-CBT, n = 146, comprising 10 weekly, 60-minute sessions that emphasized the provision of information about brain-gut interactions; self-monitoring of symptoms, their triggers, and consequences; muscle relaxation; worry control; flexible problem solving; and relapse prevention training), or 4 sessions of primarily home-based CBT requiring minimal therapist contact (MC-CBT, n = 145), in which patients received home-study materials covering the same procedures as S-CBT), or 4 sessions of IBS education (EDU, n = 145) that provided support and information about IBS and the role of lifestyle factors such as stress, diet, and exercise. The primary outcome was global improvement of IBS symptoms, based on the IBS-version of the Clinical Global Impressions-Improvement Scale. Ratings were performed by patients and board-certified gastroenterologists blinded to treatment allocation. Efficacy data were collected 2 weeks, 3 months, and 6 months after treatment completion.

RESULTS

A higher proportion of patients receiving MC-CBT reported moderate to substantial improvement in gastrointestinal symptoms 2 weeks after treatment (61.0% based on ratings by patients and 55.7% based on ratings by gastroenterologists) than those receiving EDU (43.5% based on ratings patients and 40.4% based on ratings by gastroenterologists) (P < .05). Gastrointestinal symptom improvement, rated by gastroenterologists, 6 months after the end of treatment also differed significantly between the MC-CBT (58.4%) and EDU groups (44.8%) (P = .05). Formal equivalence testing applied across multiple contrasts indicated that MC-CBT is at least as effective as S-CBT in improving IBS symptoms. Patients tended to be more satisfied with CBT vs EDU (P < .05) based on immediate posttreatment responses to the Client Satisfaction Questionnaire. Symptom improvement was not significantly related to concomitant use of medications.

CONCLUSIONS

In a randomized controlled trial, we found that a primarily home-based version of CBT produced significant and sustained gastrointestinal symptom improvement for patients with IBS compared with education. Clinicaltrials.gov no.: NCT00738920.

Predictors of response to a low-FODMAP diet in patients with functional gastrointestinal disorders and lactose or fructose intolerance

BACKGROUND

Diets low in fermentable sugars (low-FODMAP diets) are increasingly adopted by patients with functional gastrointestinal disorders (FGID), but outcome predictors are unclear.

AIM

To identify factors predictive of an efficacious response to a low-FODMAP diet in FGID patients with fructose or lactose intolerance thereby gaining insights into underlying mechanisms.

METHODS

Fructose and lactose breath tests were performed in FGID patients to determine intolerance (positive symptom score) and malabsorption (increased hydrogen or methane concentrations). Patients with fructose or lactose intolerance consumed a low-FODMAP diet and global adequate symptom relief was assessed after 6-8 weeks and correlated with pre-diet clinical symptoms and breath test results.

RESULTS

A total of 81% of 584 patients completing the low-FODMAP diet achieved adequate relief, without significant differences between FGID subgroups or types of intolerance. Univariate analysis yielded predictive factors in fructose intolerance (chronic diarrhoea and pruritus, peak methane concentrations and fullness during breath tests) and lactose intolerance (peak hydrogen and methane concentrations and flatulence during breath tests). Using multivariate analysis, symptom relief was independently and positively predicted in fructose intolerance by chronic diarrhoea [odds ratio (95% confidence intervals): 2.62 (1.31-5.27), P = 0.007] and peak breath methane concentrations [1.53 (1.02-2.29), P = 0.042], and negatively predicted by chronic nausea [0.33 (0.16-0.67), P = 0.002]. No independent predictive factors emerged for lactose intolerance.

CONCLUSIONS

Adequate global symptom relief was achieved with a low-FODMAP diet in a large majority of functional gastrointestinal disorders patients with fructose or lactose intolerance. Independent predictors of a satisfactory dietary outcome were only seen in fructose intolerant patients, and were indicative of changes in intestinal host or microbiome metabolism.

Functional urological disorders: a sensitized defence response in the bladder-gut-brain axis

Functional urological and gastrointestinal disorders are interrelated and characterized by a chronic course and considerable treatment resistance. Urological disorders associated with a sizeable functional effect include overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). Poor treatment outcomes might be attributable to untreated underlying psychological and psychiatric disorders, as the co-occurrence of functional urological and gastrointestinal disorders with mood and anxiety disorders is common. The hypothetical bladder-gut-brain axis (BGBA) is a useful framework under which this interaction can be studied, suggesting that functional disorders represent a sensitized response to earlier threats such as childhood adversity or previous traumatic events, resulting in perceived emotional and bodily distress - the symptoms of functional disorders. Psychological and physical stress pathways might contribute to such alarm falsification, and neuroticism could be a risk factor for the co-occurrence of functional disorders and affective conditions. Additionally, physical threat - either from external sources or internal sources such as infection - might contribute to alarm falsification by influencing body-brain crosstalk on homeostasis and, therefore, affecting mood, cognition, and behaviour. Multidisciplinary research and an integrated care approach is, therefore, required to further elucidate and remediate functional urological and gastrointestinal polymorphic phenotypes.

Patient-reported outcomes with lanreotide Autogel/Depot for carcinoid syndrome: An international observational study

BACKGROUND

Lanreotide Autogel/Depot effectively controls symptoms in patients with carcinoid syndrome associated with neuroendocrine tumours. Data on patient-reported outcomes are sparse.

AIM

To evaluate the effect of lanreotide on patient-reported outcomes (PROs) with carcinoid syndrome.

METHODS

This was an international, open-label, observational study of adults with neuroendocrine tumours and history of diarrhoea, receiving lanreotide for >3 months for relief of carcinoid syndrome symptoms. The primary PRO measure was satisfaction with diarrhoea control. Secondary PRO measures included severity, change in symptoms and impact on daily life of diarrhoea; and patient satisfaction with flushing control.

RESULTS

Of 273 patients enrolled, 76% were 'completely' or 'rather' satisfied with diarrhoea control; 79% reported improvement in diarrhoea with lanreotide. The proportion of patients with 'mild', 'minimal', or 'no diarrhoea' increased from 33% before treatment to 75% during treatment; 75% were unconcerned about the impact of diarrhoea on daily life. Satisfaction with flushing control amongst patients with significant flushing at treatment initiation was 73%.

CONCLUSIONS

Lanreotide treatment was associated with improvements in symptoms as well as a range of PROs in patients with neuroendocrine tumours and carcinoid syndrome (ClinicalTrials.gov: NCT01234168).

Irritable bowel syndrome: an integrated explanatory model for clinical practice

BACKGROUND

Although irritable bowel syndrome (IBS) is a symptom-based diagnosis, clinicians' management of and communication about the disorder is often hampered by an unclear conceptual understanding of the nature of the problem. We aimed to elucidate an integrated explanatory model (EM) for IBS from the existing literature for pragmatic use in the clinical setting.

METHODS

Systematic and exploratory literature searches were performed in PubMed to identify publications on IBS and EMs.

KEY RESULTS

The searches did not identify a single, integrated EM for IBS. However, three main hypotheses were elucidated that could provide components with which to develop an IBS EM: (i) altered peripheral regulation of gut function (including sensory and secretory mechanisms); (ii) altered brain-gut signaling (including visceral hypersensitivity); and (iii) psychological distress. Genetic polymorphisms and epigenetic changes may, to some degree, underlie the etiology and pathophysiology of IBS and could increase the susceptibility to developing the disorder. The three model components also fit into one integrated explanation for abdominal symptoms and changes in stool habit. Additionally, IBS may share a common pathophysiological mechanism with other associated functional syndromes.

CONCLUSIONS & INFERENCES

It was possible to elucidate an integrated, three-component EM as a basis for clinicians to conceptualize the nature of IBS, with the potential to contribute to better diagnosis and management, and dialog with sufferers.

Irritable bowel syndrome is significantly associated with somatisation in 840 patients, which may drive bloating

BACKGROUND

Psychological factors may influence persistence and perceived severity of symptoms in irritable bowel syndrome (IBS). Literature suggests that somatisation is associated with IBS. However, the relationship between IBS subtype, symptoms of IBS and somatisation is unclear.

AIM

To examine this issue in a large cohort of secondary care patients.

METHODS

Demographic and gastrointestinal (GI) symptom data were collected from 4224 adult patients via the Rome III questionnaire. Somatisation data were collected using the patient health questionnaire-12. Mean somatisation score and number of somatic symptoms were compared between IBS patients and controls with minimal GI symptoms, and between IBS subtypes using analysis of variance. Effect of level of somatisation on symptom frequency was compared according to IBS subtype using a χ(2) test.

RESULTS

840 patients met Rome III criteria for IBS, controls were 2137 patients with GI symptoms without IBS. Mean somatisation scores and number of somatic symptoms were higher in IBS vs. controls (P < 0.001), and in mixed stool pattern IBS (IBS-M), vs. IBS with constipation (IBS-C) or diarrhoea (IBS-D) (P < 0.001). High levels of somatisation were more prevalent in IBS-M (31.7%) vs. IBS-C (22.5%) or IBS-D (20.8%) (P = 0.003). For all IBS subtypes, high levels of somatisation were associated with a greater frequency of bloating or abdominal distension prior to logistic regression.

CONCLUSIONS

IBS is strongly associated with higher levels of somatisation, particularly IBS-M. Bloating may be associated with higher levels of somatisation, perhaps explaining why it can be difficult to treat.

Optimal management of constipation associated with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common chronic functional disorder of the gastrointestinal tract, meanly characterized by recurrent abdominal pain or discomfort and altered bowel habit. It is a complex disorder involving biological, environmental, and psychosocial factors. The diagnosis is achieved according to the Rome III criteria provided that organic causes have been excluded. Although IBS does not constitute a life-threatening condition, it has a remarkable prevalence and profoundly reduces the quality of life with burdening socioeconomic costs. One of the principal concerns about IBS is the lack of effective therapeutic options. Up to 40% of patients are not satisfied with any available medications, especially those suffering from chronic constipation. A correct management of IBS with constipation should evolve through a global approach focused on the patient, starting with careful history taking in order to assess the presence of organic diseases that might trigger the disorder. Therefore, the second step is to examine lifestyle, dietary habits, and psychological status. On these bases, a step-up management of disease is recommended: from fiber and bulking agents, to osmotic laxative drugs, to new molecules like lubiprostone and linaclotide. Although new promising tools for relief of bowel-movement-related symptoms are being discovered, a dedicated doctor-patient relationship still seems to be the key for success.

Adverse events appear to unblind clinical trials in irritable bowel syndrome

BACKGROUND

Clinical trial design is challenging in irritable bowel syndrome (IBS) due in part to a high placebo effect. We postulated that the mere presence of an adverse event (AE) may unmask patients in clinical trials who are assigned to the active agent, and this may lead to higher reported efficacy.

METHODS

We evaluated therapies receiving at least a Grade 1B from the American College of Gastroenterology Task Force for IBS or which passed recent phase III clinical trials. Therapies with AE data derived from less than 50 patients in each study arm were excluded. Statistically significant excess AE were identified, risk difference was calculated for each AE, and incidence of AE in the treatment arm was reported. We examined the relationship of attributable drug benefit, defined as the reciprocal of number-needed-to-treat found in literature, with various measures of AE incidence.

KEY RESULTS

Attributable drug benefit correlated significantly with average AE risk difference, calculated as treatment arm AE incidence minus placebo arm AE incidence (R(2) = 0.70, p = 0.039), and also with highest treatment arm AE incidence (R(2) = 0.70, p = 0.038) for each therapy. There were also trends toward correlation with average treatment arm AE incidence (R(2) = 0.54, p = 0.096) and highest AE risk difference (R(2) = 0.63, p = 0.059) for each therapy.

CONCLUSIONS & INFERENCES

Our study suggests that higher AE incidence on active therapy is associated with more beneficial patient-reported outcomes in IBS clinical trials. This raises the issue of spontaneous unblinding.

The impact of physical complaints, social environment, and psychological functioning on IBS patients' health perceptions: looking beyond GI symptom severity

OBJECTIVES

In the absence of a reliable biomarker, clinical decisions for a functional gastrointestinal (GI) disorder like irritable bowel syndrome (IBS) depend on asking patients to appraise and communicate their health status. Self-ratings of health (SRH) have proven a powerful and consistent predictor of health outcomes, but little is known about how they relate to those relevant to IBS (e.g., quality of life (QOL), IBS symptom severity). This study examined what psychosocial factors, if any, predict SRH among a cohort of more severe IBS patients.

METHODS

Subjects included 234 Rome III-positive IBS patients (mean age=41 years, female=78%) without comorbid organic GI disease. Subjects were administered a test battery that included the IBS Symptom Severity Scale, Screening for Somatoform Symptoms, IBS Medical Comorbidity Inventory, SF-12 Vitality Scale, Perceived Stress Scale, Beck Depression Inventory, Trait Anxiety Inventory, and Negative Interactions Scale.

RESULTS

Partial correlations identified somatization, depression, fatigue, stress, anxiety, and medical comorbidities as variables with the strongest correlations with SRH (r values=0.36-0.41, P values <0.05). IBS symptom severity was weakly associated with SRH (r=0.18, P<0.05). The final regression model explained 41.3% of the variance in SRH scores (F=8.49, P<0.001) with significant predictors including fatigue, medical comorbidities, somatization, and negative social interactions.

CONCLUSIONS

SRH are associated with psychological (anxiety, stress, depression), social (negative interactions), and extraintestinal somatic factors (fatigue, somatization, medical comorbidities). The severity of IBS symptoms appears to have a relatively modest role in how IBS patients describe their health in general.

Lubiprostone: pharmacokinetic, pharmacodynamic, safety and regulatory aspects in the treatment of constipation-predominant irritable bowel syndrome

INTRODUCTION

Lubiprostone acts locally (apical membrane of human intestinal epithelial cells) as a highly selective type-2 chloride channel activator. It was approved in the USA for chronic idiopathic constipation (January 2006) and in women aged ≥ 18 years suffering from irritable bowel syndrome with constipation (IBS-C) (April 2008). So far, the only other pro-secretory medication approved in IBS-C and currently available in USA and Europe (since August and November 2012, respectively) is linaclotide.

AREAS COVERED

This review outlines the regulatory history, pharmacokinetic, pharmacodynamic and safety data in the treatment of IBS-C with a European perspective. It is based on publicly available data, namely, published literature, drug labels and the FDA's spontaneous reporting system.

EXPERT OPINION

Although interesting pharmacodynamic data suggest that lubiprostone may have additional mechanisms of action, its beneficial effects in IBS-C must be confirmed in the actual clinical scenario taking into account the new version of European Medicines Agency's guideline. This is especially important with regard to duration of studies (recommended to be at least 6 months) to adequately assess long-term sustained efficacy, withdrawal, rebound and safety. Further research is warranted in uncertain areas (i.e., males, pediatric and elderly patients). On the basis of current data, it is still too early to draw definite conclusions on the overall risk-benefit balance for IBS-C.

Type, rather than number, of mental and physical comorbidities increases the severity of symptoms in patients with irritable bowel syndrome

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) has significant mental and physical comorbidities. However, little is known about the day-to-day burden these comorbidities place on quality of life (QOL), physical and mental function, distress, and symptoms of patients.

METHODS

We collected cross-sectional data from 175 patients with IBS, which was diagnosed on the basis of Rome III criteria (median age, 41 years; 78% women), who were referred to 2 specialty care clinics. Patients completed psychiatric interviews, a physical comorbidity checklist, the IBS Symptom Severity Scale, the IBS-QOL instrument, the Brief Symptom Inventory, the abdominal pain intensity scale, and the Short Form-12 Health Survey.

RESULTS

Patients with IBS reported an average of 5 comorbidities (1 mental, 4 physical). Subjects with more comorbidities reported worse QOL after adjusting for confounding variables. Multiple linear regression analyses indicated that comorbidity type was more consistently and strongly associated with illness burden indicators than disease counts. Of 10,296 possible physical-mental comorbidity pairs, 6 of the 10 most frequent dyads involved specific conditions (generalized anxiety, depression, back pain, agoraphobia, tension headache, and insomnia). These combinations were consistently associated with greater illness and symptom burdens (QOL, mental and physical function, distress, more severe symptoms of IBS, and pain).

CONCLUSIONS

Comorbidities are common among patients with IBS. They are associated with distress and reduced QOL. Specific comorbidities are associated with more severe symptoms of IBS.

Which psychological factors exacerbate irritable bowel syndrome? Development of a comprehensive model

OBJECTIVE

There is evidence that psychological factors affect the onset, severity and duration of irritable bowel syndrome (IBS). However, it is not clear which psychological factors are the most important and how they interact. The aims of the current study are to identify the most important psychological factors predicting IBS symptom severity and to investigate how these psychological variables are related to each other.

METHODS

Study participants were 286 IBS patients who completed a battery of psychological questionnaires including neuroticism, abuse history, life events, anxiety, somatization and catastrophizing. IBS severity measured by the IBS Severity Scale was the dependent variable. Path analysis was performed to determine the associations among the psychological variables, and IBS severity.

RESULTS

Although the hypothesized model showed adequate fit, post hoc model modifications were performed to increase prediction. The final model was significant (Chi(2)=2.2; p=0.82; RMSEA<.05) predicting 36% of variance in IBS severity. Catastrophizing (standardized coefficient (β)=0.33; p<.001) and somatization (β=0.20; p<.001) were the only two psychological variables directly associated with IBS severity. Anxiety had an indirect effect on IBS symptoms through catastrophizing (β=0.80; p<.001); as well as somatization (β=0.37; p<.001). Anxiety, in turn, was predicted by neuroticism (β=0.66; p<.001) and stressful life events (β=0.31; p<.001).

CONCLUSION

While cause-and-effect cannot be determined from these cross-sectional data, the outcomes suggest that the most fruitful approach to curb negative effects of psychological factors on IBS is to reduce catastrophizing and somatization.

Multidomain patient-reported outcomes of irritable bowel syndrome: exploring person-centered perspectives to better understand symptom severity scores

OBJECTIVES

Patient-reported outcomes assessing multiple gastrointestinal symptoms are central to characterizing the therapeutic benefit of novel agents for irritable bowel syndrome (IBS). Common approaches that sum or average responses across different illness components must be unidimensional and have small unique variances to avoid aggregation bias and misinterpretation of clinical data. This study sought to evaluate the unidimensionality of the IBS Symptom Severity Scale (IBS-SSS) and to explore person-centered cluster analytic methods for characterizing multivariate-based patient profiles.

METHODS

Ninety-eight Rome-diagnosed patients with IBS completed the IBS-SSS and a single, global item of symptom severity (UCLA Symptom Severity Scale) at pretreatment baseline of a clinical trial funded by the National Institutes of Health. k-means cluster analyses were performed on participants' symptom severity scores.

RESULTS

The IBS-SSS was not unidimensional. Exploratory cluster analyses revealed four common symptom profiles across five items of the IBS-SSS. One cluster of patients (25%) had elevated scores on pain frequency and bowel dissatisfaction, with less elevated but still high scores on life interference and low pain severity ratings. A second cluster (19%) was characterized by intermediate scores on both pain dimensions but more elevated scores on bowel dissatisfaction. A third cluster (18%) had elevated scores across all IBS-SSS subcomponents. The fourth and the most common cluster (37%) had relatively low scores on all dimensions except bowel dissatisfaction and life interference due to IBS symptoms.

CONCLUSIONS

Patient-reported outcome end points and research on IBS more generally relying on multicomponent assessments of symptom severity should take into account the multidimensional structure of symptoms to avoid aggregation bias and to optimize the sensitivity of detecting treatment effects.

Increased pain sensitivity among adults reporting irritable bowel syndrome symptoms in a large population-based study

The aim of this study was to examine whether irritable bowel syndrome (IBS) is associated with increased somatic pain sensitivity in a large population-based sample and to test whether this association was independent of sex, age, comorbid chronic pain, and psychological distress. Pain sensitivity tests included assessment of heat-pain threshold (N=4054) and pressure-pain threshold (N=4689) and of cold-pressor pain intensity and tolerance (N=10,487). Cox regression and analysis of variance (ANOVA) were used to assess the relationship between IBS and pain sensitivity in stepwise multivariate models. The prevalence of IBS symptoms meeting the ROME II criteria was 5.3%. Compared with control subjects, IBS cases had reduced cold-pressor tolerance (hazard ratio=1.4, P<.01), increased cold-pressor pain intensity ratings (z-score=+0.20, P<0.01), and lower heat-pain thresholds (z-score=-0.20, P<0.01), after adjusting for sex and age. These results were only slightly attenuated and remained significant when controlling for comorbid chronic pain and psychological distress. Results for pressure-pain threshold were not significant. Heat- and cold-pressor pain sensitivity was greatest for the IBS reporting severe chronic abdominal pain, indicating that hyperalgesia in IBS is related to degree of clinical pain rather than to the diagnosis per se. Because all pain tests were all carried out on the upper extremities, our findings indicate the presence of widespread hyperalgesia in IBS, which may be a contributing factor to the high rate of comorbid pain seen in this patient group.

Linaclotide: promising IBS-C efficacy in an era of provisional study endpoints

Recent disappointing developments in the pharmacotherapy of irritable bowel syndrome (IBS) have not dampened the enthusiasm surrounding linaclotide, a novel guanylate cyclase-C agonist for the management of constipation-predominant IBS (IBS-C). Two recent phase 3 studies reporting on a single, daily dose of linaclotide are presented in this issue of the American Journal of Gastroenterology. Importantly, these studies are the first to examine a provisional Food and Drug Administration (FDA) combined response endpoint for IBS-C, which mandates improvements of both abdominal pain and defecatory symptoms. Potential limitations of this FDA endpoint relate to a lack of inclusion of other potentially important IBS symptoms and an inability to directly compare findings with other recent IBS-C trials. Both studies successfully reached this endpoint in approximately one-third of study subjects, resulting in numbers needed to treat (NNT) of five to eight, to achieve an FDA responder. Individual symptom responses to linaclotide were seen in nearly 50% of participants, and potential explanations for these discrepancies when compared with the FDA endpoint are offered. Adequate relief measures also were assessed and, with NNTs of 3.4-6.8, compared favorably with other contemporary IBS-C studies. Overall, both linaclotide trials found the medication to be safe in terms of serious adverse events, though the secretagogue mechanism of action led to diarrhea in approximately one in five subjects. Together, these studies inspire several other important questions regarding linaclotide, including its role in the management of IBS-C relative to existing treatment options, such as lubiprostone. Greater clinical use of linaclotide will reveal whether the observed responses measured with the FDA provisional endpoint will translate into real-world experiences of improvement in IBS patients.

Safety evaluation of lubiprostone in the treatment of constipation and irritable bowel syndrome

INTRODUCTION

Lubiprostone is approved in the United States for the treatment of chronic idiopathic constipation and constipation predominant irritable bowel syndrome (IBS-C). Lubiprostone causes secretion of fluid and electrolytes in the small bowel, through the activation of chloride channels, and thereby induces laxation and improvement of bowel functions. It is generally considered to be safe and effective. Common side effects of lubiprostone include nausea, diarrhea, abdominal pain and bloating, and the rare side effect dyspnea. Likely mechanisms for these side effects may be related to lubiprostone's primary action on small bowel secretion and the associated intestinal distension, as well as smooth muscle contraction.

AREAS COVERED

This article reviews the pharmacokinetic and safety profile of lubiprostone, with particular relevance to the two FDA-approved dosages.

EXPERT OPINION

Lubiprostone acts topically in the gut lumen and is almost completely metabolized in the gut lumen. Lubiprostone's M3 metabolite can be detected in low concentrations in the serum and may be responsible for some of its side effects. However, the exact mechanisms by which the side effects are produced are currently unknown.