Systematic review of diagnostic criteria for IBS demonstrates poor validity and utilization of Rome III

Prevalence of functional disorders across Europe: a systematic review and meta-analysis

Functional Disorders (FD) refer to persistent somatic symptoms caused by changes in the functioning of bodily processes. Previous findings suggest that FD are highly prevalent, but overall prevalence rates for FD in European countries are scarce. Therefore, the aim of the present work was to estimate the point prevalence of FD in adult general populations. PubMed and Web of Science were searched from inception to June 2022. A generalized linear mixed-effects model for statistical aggregation was used for statistical analyses. A standardized quality assessment was performed, and PRISMA guidelines were followed. A total of 136 studies were included and systematically synthesized resulting in 8 FD diagnoses. The large majority of studies was conducted in the Northern Europe, Spain, and Italy. The overall point prevalence for FD was 8.78% (95% CI from 7.61 to 10.10%) across Europe, with the highest overall point prevalence in Norway (17.68%, 95% CI from 9.56 to 30.38%) and the lowest in Denmark (3.68%, 95% CI from 2.08 to 6.43%). Overall point prevalence rates for specific FD diagnoses resulted in 20.27% (95% CI from 16.51 to 24.63%) for chronic pain, 9.08% (95% CI from 7.31 to 11.22%) for irritable bowel syndrome, and 8.45% (95% CI from 5.40 to 12.97%) for chronic widespread pain. FD are highly prevalent across Europe, which is in line with data worldwide. Rates implicate the need to set priorities to ensure adequate diagnosis and care paths to FD patients by care givers and policy makers.

Clusters of community-dwelling individuals empirically derived from stool diaries correspond with clinically meaningful outcomes

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are diagnosed according to expert consensus criteria based on recall of symptoms over periods of 3 months or longer. Whether the expert opinion concords with underlying disease process and whether individual recall is accurate are both in doubt. This study aimed to identify naturally occurring clusters of individuals with respect to symptom pattern, evaluate their significance, compare cluster profiles with expert opinion and evaluate their temporal stability.

METHODS

As part of a random population study of FGID-related symptoms, we first explored the use of prospective stool and symptom diaries combined with empirical grouping of individuals into clusters using nonhierarchical cluster analysis.

RESULTS

The analysis identified two clusters of individuals, one of which was characterized by elevated scores on all domains of symptoms (26% of the sample) and one that was low to average on all domains (74% of the sample). Cluster membership was found to be stable over a long interval. Clusters were found to differ on most domains of quality-of-life (d = 0.46-0.74), self-rated health (d = -0.42) and depression (d = -0.42) but not anxiety. Prevalence of clinically diagnosed irritable bowel syndrome (IBS) was higher in the more impacted cluster (33%) compared with the healthy cluster (13%; P < 0.0001).

CONCLUSION

A naturalistic classification of individuals challenges consensus criteria in showing that some IBS individuals have a symptom experience not unlike health. The proposed approach has demonstrated temporal stability over time, unlike consensus criteria. A naturalistic disease classification system may have practical advantages over consensus criteria when supported by a decision-analytic system.

Brainstem damage is associated with poorer sleep quality and increased pain in gulf war illness veterans

AIMS

Gulf War Illness (GWI) is manifested as multiple chronic symptoms, including chronic pain, chronic fatigue, sleep problems, neuropsychiatric disorders, respiratory, gastrointestinal, and skin problems. No single target tissue or unifying pathogenic process has been identified that accounts for this variety of symptoms. The brainstem has been suspected to contribute to this multiple symptomatology. The aim of this study was to assess the role of the brainstem in chronic sleep problems and pain in GWI veterans.

MATERIALS AND METHODS

We enrolled 90 veterans (Age = 50 ± 5, 87% Male) who were deployed to the 1990-91 Gulf War and presented with GWI symptoms. Sleep quality was evaluated using the global Pittsburgh Sleep Quality Index. Pain intensities were obtained with the Brief Pain Inventory sum score. Volumes in cortical, subcortical, brainstem, and brainstem subregions and diffusion tensor metrics in 10 bilateral brainstem tracts were tested for correlations with symptom measures.

KEY FINDINGS

Poorer sleep quality was significantly correlated with atrophy of the whole brainstem and brainstem subregions (including midbrain, pons, medulla). Poorer sleep quality also significantly correlated with lower fractional anisotropy in the nigrostriatal tract, medial forebrain tract, and the dorsal longitudinal fasciculus. There was a significant correlation between increased pain intensity and decreased fractional anisotropy in the dorsal longitudinal fasciculus. These correlations were not altered after controlling for age, sex, total intracranial volumes, or additional factors, e.g., depression and neurological conditions.

SIGNIFICANCE

These findings suggest that the brainstem plays an important role in the aberrant neuromodulation of sleep and pain symptoms in GWI.

Undifferentiated Abdominal Pain in Children Presenting to the Pediatric Emergency Department

Although common, little is known about the characteristics and management of undifferentiated abdominal pain (UAP) in the pediatric emergency department (ED). This study was a 12-month retrospective study for "abdominal pain" ED visits. Patients without an identifiable diagnosis were categorized as "UAP," while others with identified disease processes were categorized as "structural gastrointestinal diagnosis (SGID)." We included 2383 (72%) visits with 869 (36.5%) UAP visits and 1514 (63.5%) SGID visits. SGID patients had more laboratory tests (811 [53.6%] vs 422 [48.6%], P = .0186), and often had multiple tests performed (565 [69.7%] vs 264 [62.6%], P = .0116). Computed tomography and ultrasound scans were more common in SGID (computed tomography: 108 [7.1%] vs 27 [3.1%], P = .0004; ultrasound: 377 [24.9%] vs 172 [19.9%], P = .0044), and laboratory results (white blood cell count, hemoglobin, albumin, C-reactive protein) were abnormal at significantly higher rates. Analyses revealed the duration of pain as primary covariate in variance of pain etiology. Clinical features, such as duration of pain, may be augmented by laboratory tests to facilitate recognition of UAP in the ED.

Irritable bowel syndrome is underdiagnosed and ineffectively managed among endurance athletes

Lower gastrointestinal (GI) symptoms are common among endurance athletes and can impair performance. Symptom characteristics are similar to irritable bowel syndrome (IBS). No previous research has examined IBS diagnosis (medically or by diagnostic criteria) within this population. The objectives of this study were to determine the prevalence of IBS among endurance athletes and examine their GI symptom management strategies. A previously validated, online questionnaire assessed IBS diagnosis, the meeting of IBS diagnostic criteria (Rome III or Manning), general GI symptoms, and symptom mitigation strategies of endurance athletes. The questionnaire was distributed to United States athletes completing a marathon, ultra-marathon, half-distance triathlon, or full-distance triathlon. Medically diagnosed IBS was reported by 2.8% of endurance athletes. The total prevalence of IBS (n = 430) was 9.8% (medical diagnosis and Rome III). Athletes with IBS experienced more frequent symptoms during exercise as well as at rest; however, only 47.6% had consulted a medical professional. Over 56% of athletes experienced at least 1 symptom sometimes, often, or always during training and competition and 18.6% had symptoms that sometimes or often interrupted/prevented training. Almost half (45.8%) of athletes and 80.0% of athletes with IBS reported trying nutritional modifications to help ease symptoms while 20.6% and 52.4% used over-the-counter medications, respectively. Novelty Most endurance athletes who suffer from IBS are undiagnosed, while even more experience GI symptoms but do not fit diagnostic criteria. Despite using various symptom management methods, endurance athletes are still experiencing symptoms and could potentially benefit from current IBS-mitigating strategies.

Questionnaire on Irritable Bowel Syndrome and Symptom Management Among Endurance Athletes Is Valid and Reliable

BACKGROUND

Gastrointestinal symptoms are reported in a large proportion of endurance athletes, with similarities in symptom type and distribution to irritable bowel syndrome (IBS).

AIMS

The objective of this study was to develop and validate a questionnaire to assess IBS diagnoses or fit to IBS diagnostic criteria in this population along with nutritional habits, gastrointestinal symptoms, and symptom management strategies.

METHODS

A 93-item Endurance Athlete Questionnaire was developed to address the objective, targeted at American endurance athletes completing a marathon, ultra-marathon, half-distance triathlon, and/or full-distance triathlon that year. Content validity was established by expert reviewers (n = 6), and face validity was evaluated by endurance athletes (n = 9). Test-retest reliability was assessed by target athletes (n = 51). Participants completed two rounds of the questionnaire, separated by 1-2 weeks. Results were analyzed using Pearson and Spearman correlations and paired comparisons.

RESULTS

Slight modifications in wording and three demographic questions were added based on the input of expert and athlete reviews. Pearson correlation coefficient of test-retest total questionnaire scores was significant at 0.839 (P < 0.001). Paired comparison of individual questions found significant differences in 10 of 236 analyzed responses; however, these did not affect fit to IBS diagnostic criteria for those without other GI diseases/disorders.

CONCLUSIONS

The Endurance Athlete Questionnaire proved to be a valid and reliable measure of IBS diagnostic criteria, gastrointestinal symptoms, nutritional habits, and symptom management strategies among endurance athletes. Future implementation will help inform gastroenterologists with endurance athlete patients and can elucidate whether certain behaviors could be contributing to athlete gastrointestinal symptoms.

A Protocol-Driven Assessment Promotes a More Accurate Diagnosis of Irritable Bowel Syndrome

A diverse range of conditions share symptoms commonly identified with irritable bowel syndrome. The objective of this study was to examine the diagnostic process in identifying additional diagnoses in women who are attending a clinic for evaluation of symptoms suggestive of irritable bowel syndrome. A retrospective audit was conducted of anonymous data gathered on consecutive female patients presenting to a specialist nurse-led service in Christchurch, New Zealand, with a provisional diagnosis of irritable bowel syndrome. A protocol containing routine pathology investigations and physical examination was used. Alarm features were identified and pertinent investigations were implemented. Rectocele was detected on rectal examination. Final diagnosis was noted and compared with baseline symptom data. Of 231 patients, 187 initially met Rome III criteria for irritable bowel syndrome. Red flags and abnormal investigations led to an alternate diagnosis in a further 27 patients. Of the 160 patients with irritable bowel syndrome, 31% were found to have a rectocele. They were seven times more likely to report a symptom associated with pelvic floor dysfunction (p < .0001) and four times more likely to report constipation (p = .0003). The use of a protocol including routine investigations and physical examination improves diagnostic yield. Pelvic floor dysfunction should be considered in those with unique symptom patterns and rectocele in the setting of irritable bowel syndrome.

Combining Rome III criteria with alarm symptoms provides high specificity but low sensitivity for functional gastrointestinal disorders in children

AIM

This study aimed to validate the Rome III criteria and alarm symptoms with regard to their ability to discriminate between organic and functional diagnoses in children with gastrointestinal complaints.

METHODS

We recruited 258 children aged four years to 17 years who consulted a paediatrician in secondary or tertiary care in Stockholm from January 2013 to May 2014 due to gastrointestinal complaints. A symptom questionnaire based on the official Questionnaire on Pediatric Gastrointestinal Symptoms Rome III, including questions on alarm symptoms, was used. A diagnostic review of their medical records was also carried out.

RESULTS

The reference diagnoses were organic (16%), pain-predominant functional gastrointestinal disorders (54%) and other functional diseases (30%). When the reported symptoms that fulfilled the Rome III criteria for pain-predominant functional gastrointestinal disorders were combined with an absence of alarm symptoms, they had a high specificity (0.90) for a functional diagnosis, but a low sensitivity (0.15). Alarm symptoms were equally common in patients with organic (83%) and functional diseases (80%, p = 0.66).

CONCLUSIONS

Combining the Rome III criteria and an absence of alarm symptoms from patient questionnaires had high specificity but low sensitivity when diagnosing pain-predominant functional gastrointestinal disorders in children seeking medical care for gastrointestinal complaints.

Rome Criteria and a Diagnostic Approach to Irritable Bowel Syndrome

Functional gastrointestinal disorders (FGIDs) account for at least 40% of all referrals to gastroenterologists. Of the 33 recognized adult FGIDs, irritable bowel syndrome (IBS) is the most prevalent, with a worldwide prevalence estimated at 12%. IBS is an important health care concern as it greatly affects patients' quality of life and imposes a significant economic burden to the health care system. Cardinal symptoms of IBS include abdominal pain and altered bowel habits. The absence of abdominal pain makes the diagnosis of IBS untenable. The diagnosis of IBS can be made by performing a careful review of the patient's symptoms, taking a thoughtful history (e.g., diet, medication, medical, surgical, and psychological history), evaluating the patient for the presence of warning signs (e.g., "red flags" of anemia, hematochezia, unintentional weight loss, or a family history of colorectal cancer or inflammatory bowel disease), performing a guided physical examination, and using the Rome IV criteria. The Rome criteria were developed by a panel of international experts in the field of functional gastrointestinal disorders. Although initially developed to guide researchers, these criteria have undergone several revisions with the intent of making them clinically useful and relevant. This monograph provides a brief overview on the development of the Rome criteria, discusses the utility of the Rome IV criteria, and reviews how the criteria can be applied clinically to diagnose IBS. In addition, a diagnostic strategy for the cost-effective diagnosis of IBS will be reviewed.

Microscopic colitis: a missed diagnosis among patients with moderate to severe irritable bowel syndrome

OBJECTIVE

Irritable bowel syndrome (IBS) is a very common condition in general practise, affecting 10-20% of the population in the Western world. The clinical picture of diarrhoea-predominant IBS (IBS-D) resembles other chronic diarrhoeic conditions, such as microscopic colitis (MC). It is impossible to separate these by clinical examinations or lab-tests that can be done in general practise. The aim of this study was to detect any missed diagnoses when only using a symptom-based approach for the diagnosis of IBS.

MATERIAL AND METHODOLOGY

We examined 87 participants diagnosed with IBS by the Rome III criteria. All the participants underwent full clinical examination, lab-tests and colonoscopy including mucosa biopsies for histological examination.

RESULTS

The histological analysis revealed four cases of MC in participants who for years had been diagnosed with IBS. We found no biochemical or clinical markers that made it possible to differentiate between IBS and MC. MC was only found in the participants diagnosed with IBS-D.

CONCLUSION

When long-lasting, unresolved diarrhoeic conditions are present in patients over 45-50 years of age, colonoscopy with biopsy should be performed to rule out MC and other pathologies before diagnosing IBS. In younger patients with pronounced watery diarrhoea, one should consider colonoscopy individually if there is no response to IBS-treatment.

Somatic Comorbidity in Chronic Constipation: More Data from the GECCO Study

Background. Comorbidity in chronic constipation has rarely been investigated, despite the fact that constipation can occur as one symptom in a number of neurological, systemic, and other nonintestinal and intestinal disorders. Methods. Of 1037 individuals with constipation identified during a telephone survey, 589 returned a postal questionnaire with valid data, asking for sociographic data, clinical symptoms, comorbid conditions, medication intake, and health care behavior related to constipation. Among them, 245 reported some somatic diagnoses and another 120 regular medication intake. They were compared to individuals without comorbid condition and presumed functional constipation (n = 215). Results. Individuals reporting a somatic comorbid condition and/or regular medication were significantly older than those with functional constipation (63.8 ± 15.8 and 43.7 ± 15.5 years, resp., p < 0.001) and had lower health and social status (both p < 0.001), but similar general life satisfaction (n.s.). Their quality-of-life was lower for the physical (p < 0.001) but not for the mental health domain (n.s.), while among those with functional constipation, the mental health domain distinguished IBS-C individuals from those with functional constipation but without pain (p < 0.001). Conclusion. In an unselected population sample with constipated individuals, those with a somatic comorbid condition outnumber those with functional constipation alone and are distinctly different with respect to age and health status.

Postinfectious and sporadic functional gastrointestinal disorders have different prevalences and rates of overlap: results from a controlled cohort study 3 years after acute giardiasis

BACKGROUND

Irritable bowel syndrome (IBS) is a common complication following gastroenteritis, and a high prevalence of postgiardiasis IBS has previously been reported. This study aims to investigate the prevalence, adjusted relative risk (RRadj), and overlap of different functional gastrointestinal disorders (FGID) according to Rome III criteria following infection with Giardia lamblia.

METHODS

All patients ≥18 years of age with verified giardiasis during an outbreak in 2004, and a control group matched by age and gender, were mailed a questionnaire 3 years later.

KEY RESULTS

The prevalence of functional dyspepsia (FD) was 25.9% in the exposed and 6.9% in the control group, RRadj: 3.9 (95% confidence intervals [CI]: 3.1-4.8). The prevalence of IBS was 47.9% and 14.3%, respectively, with RRadj: 3.4 (95% CI: 3.0-3.8). Prevalence of other gastrointestinal symptoms ranged from 70.0% vs 39.7% for bloating (RRadj: 1.8) to 8.3% vs 2.9% for nausea (RRadj: 3.0) in the Giardia and the control group, respectively. Among individuals fulfilling criteria for IBS 44% in the exposed group and 29% in the control group also fulfilled criteria for FD. IBS subtypes based on Rome III criteria (stool consistency) showed poor agreement with subtypes based on frequency of bowel movements (Kappa-values: 0.17 and 0.27).

CONCLUSIONS & INFERENCES

There were high prevalences and RRs of IBS, FD and other gastrointestinal symptoms following acute giardiasis, and a high degree of overlap between the disorders. The agreement between different IBS subtype criteria varied, and there were also differences between the exposed and control group.

Irritable Bowel Syndrome: A Global Challenge Among Medical Students

Irritable bowel syndrome (IBS) has been identified as one of the more highly prevalent and costly gastrointestinal disorders. Despite its uncertain etiology, risk factors, such as stress and academic load, are well correlated with the prevalence of the disease. Being in one of the most stressful and challenging environments, medical students are predisposed to have high rates of IBS. The socioeconomic burden of the disease on its sufferers is devastating as their quality of life is reduced, mandating additional health care precautions. The aim of this article, therefore, is to review the current literature about IBS among medical students, its prevalence, associated risk factors, and diagnostic criteria. Additionally, different solutions and management options are recommended to control the disease.

Systematic review with meta-analysis: the prevalence of bile acid malabsorption in the irritable bowel syndrome with diarrhoea

BACKGROUND

Irritable bowel syndrome is a widespread disorder with a marked socioeconomic burden. Previous studies support the proposal that a subset of patients with features compatible with diarrhoea-predominant IBS (IBS-D) have bile acid malabsorption (BAM).

AIM

To perform a systematic review and meta-analysis to assess the prevalence of BAM in patients meeting the accepted criteria for IBS-D.

METHODS

MEDLINE and EMBASE were searched up to March 2015. Studies recruiting adults with IBS-D, defined by the Manning, Kruis, Rome I, II or III criteria and which used 23-seleno-25-homotaurocholic acid (SeHCAT) testing for the assessment of BAM were included. BAM was defined as 7 day SeHCAT retention of <10%. We calculated the rate of BAM and 95% confidence intervals (CI) using a random effects model. The methodological quality of included studies was evaluated using the Quality Assessment for Diagnostic Accuracy Studies (QUADAS-2).

RESULTS

The search strategy identified six relevant studies comprising 908 individuals. The rate of BAM ranged from 16.9% to 35.3%. The pooled rate was 28.1% (95% CI: 22.6-34%). There was significant heterogeneity in effect sizes (Q-test χ(2)  = 17.9, P < 0.004; I(2)  = 72.1%). The type of diagnostic criteria used or study country did not significantly modify the effect.

CONCLUSIONS

These data provide evidence that in excess of one quarter of patients meeting accepted criteria for IBS-D have bile acid malabsorption. This distinction has implications for the interpretation of previous studies, as well as contemporaneous clinical practice and future guideline development.

Potential Causes and Present Pharmacotherapy of Irritable Bowel Syndrome: An Overview

BACKGROUND

Irritable bowel syndrome (IBS) is currently one of the most common disorders of the digestive system in the Western society. Almost 2 out of 10 people suffer from IBS with women being more affected than men. IBS is associated with abdominal pain, bloating and altered stool consistency and imposes a heavy burden for the affected patients.

SUMMARY

The pathophysiology of IBS remains elusive although potential causes have been suggested, such as a deranged brain-gut signaling, hypersensitivity of visceral sensory afferent fibers, bacterial gastroenteritis, small intestinal bacterial overgrowth (SIBO), genetic alterations and food sensitivity. Targets for the pharmacotherapy of IBS include the serotonergic and opioidergic system, and the microbial population of the gut. Alternative therapies like traditional Chinese medicine have shown some success in the combat against IBS. Key Messages: Many therapeutics for the treatment of IBS have emerged in the past; however, only a few have met up with the expectations in larger clinical trials. Additionally, the multifactorial etiology of IBS and its variety of cardinal symptoms requires an individual set of therapeutics. This review provides a short overview of potential causes and current pharmacological therapeutics and of additional and alternative therapies for IBS.

Molecular and cellular mechanisms of tight junction dysfunction in the irritable bowel syndrome

The pathophysiological mechanisms of the irritable bowel syndrome (IBS), one of the most prevalent gastrointestinal disorders, are complex and have not been fully elucidated. The present study aimed to investigate the molecular and cellular mechanisms of tight junction (TJ) dysfunction in IBS. Intestinal tissues of IBS and non‑IBS patients were examined to observe cellular changes by cell chemical tracer electron microscopy and transmission electron microscopy, and intestinal claudin‑1 protein was detected by immunohistochemistry, western blot analysis and fluorescence quantitative polymerase chain reaction. Compared with the control group, TJ broadening and the tracer extravasation phenomenon were observed in the diarrhea‑predominant IBS group, and a greater number of neuroendocrine cells and mast cells filled with high‑density particles in the endocrine package pulp as well as a certain extent of vacuolization were present. The expression of claudin‑1 in diarrhea‑predominant IBS patients was decreased, while it was increased in constipation‑predominant IBS patients. In conclusion, the results of the present study indicated that changes in cellular structure and claudin‑1 levels were associated with Tjs in IBS.

Effect of Changkang Fang on serotonin transporter expression in brain-gut axis of visceral hypersensitive rats with irritable bowel syndrome

AIM: To investigate the effect of Changkang Fang on the expression of serotonin transporter (SERT) in the brain-gut axis of visceral hypersensitive rats with irritable bowel syndrome (IBS).

METHODS: Seventy-two male immature SD rats were randomly divided into either a blank control group or a model group. AL-Chaer's modeling method was used in this study. After successful modeling, the model rats were randomly divided into a model group, a Western medicine group, high-, medium- and low-dose Chinese medicine groups. After 70 d, brain and intestinal mucosal tissues were taken for detecting the expression of SERT by immunohistochemistry.

RESULTS: The expression levels of SERT in intestinal mucosal and brain tissues of visceral hypersensitive IBS rats were significantly lower compared with normal controls (P < 0.05, P < 0.001). The expression levels of SERT in intestinal mucosal and brain tissues were significantly improved in the high-dose Chinese medicine group (P < 0.001 for both) and the medium-dose Chinese medicine group (P < 0.001, P < 0.05).

CONCLUSION: Changkang Fang can regulate the expression of SERT in the brain-gut axis of visceral hypersensitive IBS rats.

How individuals with the irritable bowel syndrome describe their own symptoms before formal diagnosis

AIM

To investigate how individuals fulfilling the Rome II criteria for irritable bowel syndrome (IBS) spontaneously described their symptoms.

METHOD

From a general population, 1,244 randomly sampled adults were asked to describe their gastrointestinal symptoms (if any) verbally, in their own words, at a semi-structured interview. Their own descriptions were sorted into five symptom clusters. The participants independently completed a written questionnaire (the Rome II Modular Questionnaire (RMIIMQ)).

RESULTS

A total of 601 participants reported at least one gastrointestinal symptom, and 128 had IBS according to the RMIIMQ. After exclusion of organic causes, previously diagnosed IBS, or additional gastrointestinal diagnosis, 81 participants with IBS according to RMIIMQ remained. Five participants (6%) described symptoms included in the full definition of IBS, but none fulfilled the Rome II criteria completely. Abdominal pain or other IBS-related symptoms were reported by 64 (79%), and 12 (15%) did not report any IBS-like symptom.

CONCLUSION

Previously undiagnosed individuals, who fulfil criteria for Rome II-IBS, often express their complaints in words that do not fit into the current diagnostic criteria.

Distress criterion influences prevalence rates of functional gastrointestinal disorders

Background

Functional gastrointestinal disorders (FGID) are defined by a combination of chronic or recurrent gastrointestinal symptoms. Prevalence rates of FGID are high. Symptoms are associated with distress, and sufferers show high stress levels. However, the current diagnostic criteria do not consider subjective distress elicited by the symptoms, thus potentially leading to overestimated prevalence rates. The aim of this study was to explore the reduction in prevalence rates when distress is considered in the diagnostic criteria.

Methods

In this web-based study, FGID were diagnosed using the Rome II criteria. Prevalence rates with and without subjective distress elicited by the symptoms were computed. Additionally, stress levels and stress reactivity were assessed.

Results

Prevalence rates of FGID in our sample were similar to those in other studies. However, when considering the distress criterion, on average, a decrease of 38.51% was found in the prevalence rates of FGID. Sufferers who were subjectively distressed by their symptoms reported significantly higher stress levels than non-distressed subjects (all p < 0.001).

Conclusions

The consideration of a criterion of subjective distress in the diagnosis of FGID has consequences for actual prevalence rates of FGID. Distressed subjects differ markedly from non-distressed subjects in terms of their stress levels. The inclusion of a distress criterion in the ongoing development of diagnostic criteria for FGID is therefore warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-014-0215-9) contains supplementary material, which is available to authorized users.

Systematic review: the perceptions, diagnosis and management of irritable bowel syndrome in primary care--a Rome Foundation working team report

OBJECTIVE

To review studies on the perceptions, diagnosis and management of irritable bowel syndrome (IBS) in primary care.

METHODS

Systematic searches of PubMed and Embase.

RESULTS

Of 746 initial search hits, 29 studies were included. Relatively few primary care physicians were aware of (2-36%; nine studies) or used (0-21%; six studies) formal diagnostic criteria for IBS. Nevertheless, most could recognise the key IBS symptoms of abdominal pain, bloating and disturbed defaecation. A minority of primary care physicians [7-32%; one study (six European countries)] preferred to refer patients to a specialist before making an IBS diagnosis, and few patients [4-23%; three studies (two European, one US)] were referred to a gastroenterologist by their primary care physician. Most PCPs were unsure about IBS causes and treatment effectiveness, leading to varied therapeutic approaches and broad but frequent use of diagnostic tests. Diagnostic tests, including colon investigations, were more common in older patients (>45 years) than in younger patients [<45 years; five studies (four European, one US)].

CONCLUSIONS

There has been much emphasis about the desirability of an initial positive diagnosis of IBS. While it appears most primary care physicians do make a tentative IBS diagnosis from the start, they still tend to use additional testing to confirm it. Although an early, positive diagnosis has advantages in avoiding unnecessary investigations and costs, until formal diagnostic criteria are conclusively shown to sufficiently exclude organic disease, bowel investigations, such as colonoscopy, will continue to be important to primary care physicians.

Current and emerging pharmacotherapeutic options for irritable bowel syndrome

Treatment of irritable bowel syndrome (IBS) is challenging for both primary care physicians and gastroenterologists because of the heterogeneity of the patient population and the multifactorial pathophysiologies responsible for the symptoms in IBS. This review focuses on the current and emerging pharmacological treatments for IBS. Many of the current medications used to treat this disorder have distinct properties such as efficacy for different symptoms, safety profiles, contraindications, costs, dosing regimens, treatment duration and long-term data. All of these factors, in addition to patient preference and cognitive, food and environmental triggers, must be considered prior to any medication selection. This review will focus on randomized controlled trials with a general uniformity in study design, a rigorous patient selection and appropriate treatment durations. We will also discuss other exciting emerging treatments for IBS such as the µ-opioid receptor (agonists and antagonists), selective κ-opioid receptor agonists, anti-inflammatory drugs, serotonergic agents, bile acid modulators and intestinal bile acid transporters, which may prove promising in treating our patients.

The microbiota-gut-brain axis in functional gastrointestinal disorders

Functional gastrointestinal disorders (FGIDs) are highly prevalent and pose a significant burden on health care and society, and impact patients' quality of life. FGIDs comprise a heterogeneous group of disorders, with unclear underlying pathophysiology. They are considered to result from the interaction of altered gut physiology and psychological factors via the gut-brain axis, where brain and gut symptoms are reciprocally influencing each other's expression. Intestinal microbiota, as a part of the gut-brain axis, plays a central role in FGIDs. Patients with Irritable Bowel Syndrome, a prototype of FGIDs, display altered composition of the gut microbiota compared with healthy controls and benefit, at the gastrointestinal and psychological levels, from the use of probiotics and antibiotics. This review aims to recapitulate the available literature on FGIDs and microbiota-gut-brain axis.

Irritable bowel syndrome: The evolution of multi-dimensional looking and multidisciplinary treatments

Irritable bowel syndrome (IBS) is common in the society. Among the putative pathogeneses, gut dysmotility results in pain and disturbed defecation. The latter is probably caused by the effect of abnormal gut water secretion. The interaction between abnormal gas accumulation, abdominal pain and bloating remains controversial. Visceral hypersensitivity and its modification along with the central transmission are the characteristics of IBS patients. The identification of biologic markers based on genetic polymorphisms is undetermined. Imbalanced gut microbiota may alter epithelial permeability to activate nociceptive sensory pathways which in turn lead to IBS. Certain food constituents may exacerbate bowel symptoms. The impact of adult and childhood abuses on IBS is underestimated. Using the concept of biopsychosocial dysfunction can integrate multidimensional pathogeneses. Antispasmodics plus stool consistency modifiers to treat the major symptoms and defecation are the first-line drug treatment. New drugs targeting receptors governing bowel motility, sensation and secretion can be considered, but clinicians must be aware of their potential serious side effects. Psychiatric drugs and modalities may be the final options for treating intractable subjects. Probiotics of multi-species preparations are safe and worth to be considered for the treatment. Antibiotics are promising but their long-term safety and effectiveness are unknown. Diet therapy including exclusion of certain food constituents is an economic measure. Using relatively safe complementary and alternative medicines (CAMs) may be optional to those patients who failed classical treatment. In conclusion, IBS is a heterogeneous disorder with multidimensional pathogeneses. Personalized medicines with multidisciplinary approaches using different classes of drugs, psychiatric measures, probiotics and antibiotics, dietary therapy, and finally CAMs, can be considered.

Pathogenesis of irritable bowel syndrome--review regarding associated infection and immune activation

There is increasing evidence regarding the role of immune activation in the etiology of irritable bowel syndrome (IBS), which has been mainly been shown in studies investigating mechanisms of postinfectious IBS (PI-IBS). Exposure to intestinal infection induces persistent low-grade systemic and mucosal inflammation, which is characterized by an altered population of circulating cells, mucosal infiltration of immune cells and increased production of various cytokines in IBS patients. Recent studies have also indicated an increased innate immune response in these patients by evaluating expression and activation of Toll-like receptors (TLRs). These findings suggest that immune activation may play a crucial role in the pathogenesis of IBS. In addition, psychological stress has been reported to be one of the factors that induces immune activation. However, it remains unknown whether immune activation in IBS patients is largely dependent on infectious gastroenteritis and/or psychological stress. Additional studies are necessary to understand the precise mechanism of immune activation and its relationship to the development of IBS.

Validation of the Rome III criteria for the diagnosis of irritable bowel syndrome in secondary care

BACKGROUND & AIMS

There are few validation studies of existing diagnostic criteria for irritable bowel syndrome (IBS). We conducted a validation study of the Rome and Manning criteria in secondary care.

METHODS

We collected complete symptom, colonoscopy, and histology data from 1848 consecutive adult patients with gastrointestinal symptoms at 2 hospitals in Hamilton, Ontario; the subjects then underwent colonoscopy. Assessors were blinded to symptom status. Individuals with normal colonoscopy and histopathology results, and no evidence of celiac disease, were classified as having no organic gastrointestinal disease. The reference standard used to define the presence of true IBS was lower abdominal pain or discomfort in association with a change in bowel habit and no organic gastrointestinal disease. Sensitivity, specificity, and positive and negative likelihood ratios, with 95% confidence intervals, were calculated for each diagnostic criteria.

RESULTS

In identifying patients with IBS, sensitivities of the criteria ranged from 61.9% (Manning) to 95.8% (Rome I), and specificities from 70.6% (Rome I) to 81.8% (Manning). Positive likelihood ratios ranged from 3.19 (Rome II) to 3.39 (Manning), and negative likelihood ratios from 0.06 (Rome I) to 0.47 (Manning). The level of agreement between diagnostic criteria was greatest for Rome I and Rome II (κ = 0.95), and lowest for Manning and Rome III (κ = 0.59).

CONCLUSIONS

Existing diagnostic criteria perform modestly in distinguishing IBS from organic disease. There appears to be little difference in terms of accuracy. More accurate ways of diagnosing IBS, avoiding the need for investigation, are required.

Influence of Fagopyrum cymosum tablets on immune inflammation and visceral hypersensitivity in a rat model of diarrhea-predominant irritable bowel syndrome

AIM: To determine the influence of Fagopyrum cymosum tablets on immune inflammation and visceral hypersensitivity in a rat model of diarrhea-predominant irritable bowel syndrome (IBS).

METHODS: IBS was induced in neonatal rats by feeding a high lactose diet, chronic bandaged-stress and inserting the tail. Rats were randomly divided into six groups: a normal control group (group A), a model group (group B), high-, medium- and low-dose Fagopyrum cymosum groups (group C, D and E), and a Gushen Chang'an group (group F). Groups C, D and E received oral administration of 6, 3 and 1.5 g/(kg•d) of Fagopyrum cymosum tablets, respectively, once every day for four weeks; group F received oral administration of 2 g/(kg•d) of Gushen Chang'an; Groups A and B received oral administration of equal volume of normal saline. The colon motion, abdominal withdrawal reflex (AWR) of colorectal distention and abdominal electrical activity were observed. Radioimmunoassay was used to detect serum levels of tumor necrosis factor-α (TNF-α), interleukin 17 (IL-17), IL-10, substance P (SP) and calcitonin gene-related peptide (CGRP). Fluorescent quantitative PCR was used to detect the expression of 5-hydroxytryptamine (5-HT), 5-hydroxytryptamine 3 receptor (5-HT3R), neurokinin receptor 1 (NK1R) and intracellular adhesion molecule-1 (ICAM-1) mRNAs in the intestinal tissue.

RESULTS: Fagopyrum cymosum could decrease colon motion and visceral hypersensitivity in IBS rats (P < 0.05 or 0.01). In the Fagopyrum cymosum treatment groups, serum levels of TNF-α (2.81 ng/L ± 0.67 ng/L, 2.76 ng/L ± 0.31 ng/L, 2.91 ng/L ± 0.77 ng/L vs 3.77 ng/L ± 0.44 ng/L), IL-17 (2.01 ng/L ± 0.76 ng/L, 2.14 ng/L ± 0.29 ng/L, 1.98 ng/L ± 0.11 ng/L vs 2.47 ng/L ± 0.33 ng/L) and SP (38.22 pg/mL ± 3.15 pg/mL, 37.55 pg/mL ± 2.63 pg/mL, 42.01 pg/mL ± 3.79 pg/mL vs 43.19 pg/mL ± 4.28 pg/mL) were significantly lower, and those of IL-10 (137.25 ng/L ± 6.2 ng/L, 135.90 ng/L ± 4.4 ng/L, 121.70 ng/L ± 5.11 ng/L vs 82.09 ng/L ± 5.33 ng/L) and CGRP (155.09 ng/L ± 4.38 ng/L, 142.02 ng/L ± 2.44 ng/L, 158.25 ng/L ± 4.02 ng/L vs 107.31 ng/L ± 3.96 ng/L) were significantly higher than those in the model group (all P < 0.05 or 0.01). The mRNA expression of 5-HT (0.74 ± 0.43, 0.97 ± 0.91, 0.66 ± 0.29 vs 1.27 ± 0.45), 5-HT3R (1.01 ± 0.35, 1.14 ± 0.76, 1.47 ± 0.65 vs 1.61 ± 0.03), NK1R (1.07 ± 0.58, 0.98 ± 0.67, 0.88 ± 0.79 vs 1.47 ± 0.94) and ICAM-1 (0.81 ± 0.55, 0.96 ± 0.19, 0.72 ± 0.93 vs 1.33 ± 0.26) in the intestinal tissue was down-regulated after treatment with Fagopyrum cymosum tablets (P < 0.05 or 0.01), especially in the high-dose group.

CONCLUSION: Fagopyrum cymosum tablets can reduce visceral hypersensitivity and inhibit inflammatory immune response in IBS-D rats in a concentration-dependent manner.

Comparison of Manning, Rome I, II, and III, and Asian diagnostic criteria: report of the Multicentric Indian Irritable Bowel Syndrome (MIIBS) study

BACKGROUND

Attempts to diagnose and subtype irritable bowel syndrome (IBS) by symptom-based criteria have limitations, as these are developed in the West and might not be applicable in other populations.

OBJECTIVES

This study aimed to compare different criteria for diagnosing and subtyping of IBS in India.

METHOD

Manning's and the Rome I, II, and III criteria as well as the Asian criteria were applied to 1,618 patients (from 17 centers in India) with chronic lower gastrointestinal (GI) symptoms with no alarm features and negative investigations.

RESULTS

Of 1,618 patients (aged 37.5 [SD 12.6] years; 71.2% male), 1,476 (91.2%), 1,098 (67.9%), 649 (40.1%), 849 (52.5%), and 1,206 (74.5%) fulfilled Manning's, Rome I, II, and III, and the Asian criteria, respectively. The most common reason for not fulfilling the criteria was absence of the following symptoms: "more frequent stools with onset of pain," "loose stool with onset of pain," "relief of pain with passage of stool," "other abdominal discomfort/bloating," and, in a minority, not meeting the duration criterion of 3 months/12 weeks. By stool frequency, constipation-predominant IBS (<3 stools/week) was diagnosed in 319 (19.7%), diarrhea-predominant IBS (>3 stools/day) in 43 (2.7%), and unclassified in 1,256 (77.6%). By Bristol stool form, constipation, diarrhea, and unclassified were diagnosed in 655 (40.5%), 709 (43.8%), and 254 (15.7%) patients, respectively. By their own perception, 462 (28.6%), 541 (33.4%), and 452 (27.9%) patients reported constipation-predominant, diarrhea-predominant, and alternating types, respectively.

CONCLUSION

By Manning's and the Asian criteria, a diagnosis of IBS was made frequently among Indian patients with chronic functional lower GI symptoms with no alarm features; the Rome II criteria gave the lowest yield. By the stool frequency criteria, a majority of patients had unclassified pattern, unlike by the stool form and patients' perception of their symptoms.

Drug development for the irritable bowel syndrome: current challenges and future perspectives

Medications are frequently used for the treatment of patients with the irritable bowel syndrome (IBS), although their actual benefit is often debated. In fact, the recent progress in our understanding of the pathophysiology of IBS, accompanied by a large number of preclinical and clinical studies of new drugs, has not been matched by a significant improvement of the armamentarium of medications available to treat IBS. The aim of this review is to outline the current challenges in drug development for IBS, taking advantage of what we have learnt through the Rome process (Rome I, Rome II, and Rome III). The key questions that will be addressed are: (a) do we still believe in the "magic bullet," i.e., a very selective drug displaying a single receptor mechanism capable of controlling IBS symptoms? (b) IBS is a "functional disorder" where complex neuroimmune and brain-gut interactions occur and minimal inflammation is often documented: do we need to target gut motility, visceral sensitivity, or minimal inflammation? (c) are there validated biomarkers (accepted by regulatory agencies) for studies of sensation and motility with experimental medications in humans? (d) do animal models have predictive and translational value? (e) in the era of personalized medicine, does pharmacogenomics applied to these medications already play a role? Finally, this review will briefly outline medications currently used or in development for IBS. It is anticipated that a more focused interaction between basic science investigators, pharmacologists, and clinicians will lead to better treatment of IBS.

Diagnostic criteria in IBS: useful or not?

There are a number of reasons to establish the accurate diagnosis of irritable bowel syndrome (IBS): to relieve patient uncertainty; to avoid adverse effects of unnecessary medications or treatments; to avoid unnecessary diagnostic procedures and surgeries; to conserve limited healthcare resources; and, of course, to initiate the most appropriate treatment. However, making the diagnosis of IBS remains difficult because it is clinically heterogeneous, no biological marker to detect it exists, many other diseases share the same clinical manifestations and it is often difficult for both physicians and patients to accept the uncertainty of a symptom-based diagnosis. Different diagnostic criteria have been developed during the last 4 decades but none have proved to be an ideal method of accurately diagnosing IBS. Just as importantly, physicians are frequently unaware of published guidelines or consciously ignore these diagnostic criteria. Most clinicians still believe IBS is a diagnosis of exclusion and not a positive diagnosis based on history, physical examination, use of published diagnostic criteria such as the Rome III criteria, and the absence of alarm features. In the sections to follow we will address the inherent difficulties of diagnosing IBS, highlight the importance of symptom-based diagnoses to help reign in soaring healthcare costs, and discuss future strategies that may enable a more cost-efficient diagnosis of IBS.