Diagnosis and management of IBS

Vitamin D in Irritable Bowel Syndrome: Exploring Its Role in Symptom Relief and Pathophysiology

Irritable Bowel Syndrome (IBS) is a chronic functional gastrointestinal disorder. Despite its common occurrence, the pathophysiology of IBS remains not fully understood. Emerging evidence suggests that IBS is a multifactorial condition characterized by low-grade inflammation, immune system activation, impaired gut permeability, intestinal hypersensitivity, and alterations in intestinal microbiota. Recent data have highlighted the potential role of vitamin D in modulating these underlying mechanisms. Vitamin D is known to influence various cellular processes, including the regulation of the gut microbiome, immune response modulation, and anti-inflammatory effects, which may alleviate the altered gut function observed in IBS. Research indicates that individuals with IBS often have lower levels of vitamin D compared to healthy controls, suggesting a possible link between vitamin D deficiency and IBS. Vitamin D supplementation has been associated with improvements in IBS symptoms, such as bloating, flatulence, abdominal pain, constipation, and overall quality of life. The mechanisms by which vitamin D exerts these effects may involve direct or indirect modulation of immune responses, the production of antimicrobial peptides, and the regulation of gene expression related to serotonergic metabolism. Despite these promising findings, the exact pathways through which vitamin D affects IBS pathophysiology remain unclear. The aim of this review is to outline the current knowledge and evidence regarding these mechanisms, as well as the therapeutic potential of vitamin D supplementation in IBS patients. Exploring the connection between vitamin D and IBS may pave the way for innovative interventions, enhancing both management strategies and the quality of life for those affected by the disorder.

Can We Modulate Our Second Brain and Its Metabolites to Change Our Mood? A Systematic Review on Efficacy, Mechanisms, and Future Directions of "Psychobiotics"

Psychobiotics, live microorganisms that provide mental health by interacting with the gut microbiota, are emerging as a promising therapeutic option for psychiatric and neurodevelopmental disorders. Their effectiveness in addressing conditions such as depression, anxiety, insomnia, stress, autism spectrum disorder (ASD), and eating disorders were examined through a comprehensive analysis of existing studies up to the first half of 2024, based on data from reliable electronic databases. We found that psychobiotics can significantly reduce symptoms of various psychiatric disorders by influencing neurotransmitter levels, regulating the hypothalamic-pituitary-adrenal (HPA) axis, and improving gut barrier function through short-chain fatty acids (SCFAs) and other metabolites. However, several limitations were identified, including inconsistent study methodologies, small sample sizes, and a lack of data on long-term safety. Addressing these limitations through rigorous research is essential for establishing standardized protocols and fully confirming the therapeutic potential of psychobiotics. In conclusion, psychobiotics show great promise as complementary treatments for mental health conditions, but continued research is necessary to refine their application and integrate them into clinical practice effectively.

The Efficacy of the Low-FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) Diet in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis

Irritable bowel syndrome (IBS) is frequently observed in clinical practice and affects people from different parts of the world. The pathogenesis and aetiology are not well-defined or fully understood; however, altered bowel movements, psychological factors, and visceral hypersensitivity may contribute to symptoms via a pathway mediated by serotonin and other enteric neurotransmitters. Altered bowel movements, including diarrhoea and constipation, abdominal pain relieved by passing flatus, and bloating are the main salient features of this condition. This systematic review and meta-analysis aimed to determine the effectiveness and efficacy of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (low-FODMAP) diet in these patients. Systematic searches were conducted on PubMed, Medline, Google Scholar, and Cochrane Library. Randomised controlled trials (RCTs), systematic trials and cohort studies that included keywords about IBS and a low-FODMAP diet were included. Exclusion criteria included studies that were not in the English language, not relevant to IBS, diet-related to inflammatory bowel disease, or not pertinent to the subject. A total of 41 studies were included in this systematic review and meta-analysis. There was significant heterogeneity among the RCTs; hence, a random-effects model was used. The systematic review included a total of 8460 patients across 36 studies, with follow-up durations ranging from 11 to 16 months. Specifically, the meta-analysis included 15 RCTs with 1118 participants and follow-up durations from two days to nine weeks and six cohort studies including 292 patients with follow-up durations from two weeks to two years. The risk ratio (RR) was 1.21 (95% confidence interval= 0.98-1.51), and the I2 value ​​​​​was 63% for global symptom improvement with a low-FODMAP diet using a random-effects model. There was a low risk of bias in the RCTs. Five studies were included evaluating the effect of a low-FODMAP diet on quality of life, and these studies did not show any statistically significant benefit of a low-FODMAP diet on quality of life, although a mean difference of 4.59 (95% CI 1.50-7.67) was observed. The risk of bias was moderate to severe in the observational studies included in this review. Food intolerance is increasingly recognised as a contributory factor in IBS, and its role in the pathogenesis and precipitation of symptoms is being explored. Specific mechanisms include the fermentation of FODMAPs by the gut microbiota, leading to gas production and subsequent symptoms.

Psychopathology and the Validity of Gastrointestinal Symptom Reporting as Revealed Through Cluster Analyses of MMPI-2-RF Results

BACKGROUND

Psychological state, self-reported gut symptoms, and somatic complaints are recognized relationships that can impact health assessment and subsequent treatment.

AIM

To investigate the impact of psychological state and personality on symptom self-reporting and somatization.

METHODS

Sixty-two (62) participants from the Hunter region of NSW (Australia) undertook a survey of health and lifestyle along with an MMPI-2-RF assessment of personality, psychopathology, and test-taking attitude. Participants also completed the Rome Criteria to assess functional gastrointestinal disorders (FGIDs). To assist the interpretation of MMPI-2-RF results, clustering was applied to identify similar responses and sub-cohort profiles of reporting.

RESULTS

Cluster analysis revealed four sub-cohorts, stratified by psychopathology, gut-related symptoms, and the validity of self-reported somatic complaints. Sample clustering identified one sub-cohort defined by high rates of negative affectivity and suicidal ideation. Apart from these differences, clusters were uniform for age, sex, smoking, mental health diagnoses, as well as for gut-related conditions.

CONCLUSION

Results provide further evidence of the interaction of the gut-brain axis and its relationship to serious mental health conditions. It also points to the need to assess the veracity of self-reported symptomatology that may be both pathognomonic for psychopathology but might also be a consequence of gut dysbiosis. Clustering assisted these investigations by defining distinct sub-cohorts based on participant MMPI-2-RF responses.

The Efficacy of Probiotics, Prebiotics, Synbiotics, and Fecal Microbiota Transplantation in Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with gut microbiota imbalance playing a significant role. There are increasing numbers of research studies exploring treatment options involving probiotics, prebiotics, synbiotics, and fecal microbiota transplantation (FMT), but it is still uncertain which treatment option is superior. The research was conducted on various databases and unpublished trial data (up to February 2023). Randomized controlled trials (RCTs) were screened for adult patients with IBS comparing interventions with placebo. Probiotics, prebiotics, synbiotics, and FMT were assessed for their impact using mean difference and Bayesian network meta-analysis. Out of 6528 articles, 54 were included for probiotics, 7 for prebiotics/synbiotics, and 6 for FMT. Probiotics showed improvement in IBS symptoms, particularly with Bifidobacterium and Lactobacillus strains. Prebiotics and synbiotics did not show significant improvement. Network meta-analysis indicated the favorable effects of probiotics (OR = 0.53, 95% CI, 0.48 to 0.59) and FMT (OR = 0.46, 95% CI, 0.33 to 0.64) on IBS, with no serious adverse events reported. In short, probiotics and FMT are effective for managing IBS, with Bifidobacterium and Lactobacillus being dominant strains. However, the most effective probiotic combination or strain remains unclear, while prebiotics and synbiotics did not show significant improvement.

The Possible Synergistic Pharmacological Effect of an Oral Berberine (BBR) and Curcumin (CUR) Complementary Therapy Alleviates Symptoms of Irritable Bowel Syndrome (IBS): Results from a Real-Life, Routine Clinical Practice Settings-Based Study

Irritable bowel syndrome (IBS) is a prevalent chronic functional gastrointestinal disorder, characterised by recurrent abdominal discomfort and altered bowel movements. IBS cause a significantly negative impact on quality of life (QoL). Growing pharmacological evidence suggests that berberine (BBR) and curcumin (CUR) may mitigate IBS symptoms through multiple complementary synergistic mechanisms, resulting in the attenuation of intestinal inflammation and regulation of bowel motility and gut functions. In the present observational study conducted under real-life routine clinical practice settings, 146 patients diagnosed with IBS were enrolled by general practitioner clinics and pharmacies in Belgium. For the first time, this study assessed the potential synergistic pharmacological effect of a combined oral BBR/CUR supplement (Enterofytol® PLUS, containing 200 mg BBR and 49 mg CUR) (two tablets daily for 2 months), serving as complementary therapy in the management of IBS. Following the 2-month supplementation, significant improvements were observed in the patients' IBS severity index (IBSSI) (47.5%) and all the primary IBS symptoms, such as abdominal discomfort (47.2%), distension (48.0%), intestinal transit (46.8%), and QoL (48.1%) (all p < 0.0001). The improvement in the patients' IBSSI was independent of age, sex, and IBS sub-types. The patients' weekly maximum stool passage frequency decreased significantly (p < 0.0001), and the stool status normalized (p < 0.0001). The patients' need for concomitant conventional IBS treatment decreased notably: antispasmodics by 64.0% and antidiarrhoeals by 64.6%. Minor adverse effects were reported by a small proportion (7.1%) of patients, mostly gastrointestinal. The majority (93.1%) experienced symptom improvement or resolution, with a high satisfaction rate (82.6%) and willingness to continue the supplementation (79.0%). These findings support the potential synergistic pharmacological role of BBR and CUR in IBS, and their co-supplementation may alleviate IBS symptoms and improve QoL.

Psychological distress in individuals with irritable bowel syndrome: the roles of body image and self-criticism

Objective

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder associated with reduced quality of life and psychological distress (PD) including anxiety and depression. The mechanisms linking IBS to PD are unclear. Previous studies showed that body image and self-criticism may be contributory factors. Thus, the objective of this study was to test the potential mediating roles of these factors in the relationship between IBS and PD.

Method

507 adults participated, including 142 with IBS (Mean age = 31.9, SD = 11.7), and 365 healthy peers (Mean age = 26.2, SD = 6.4), ranging in age from 18 to 75. The majority of participants were women (78%). Self-report measures assessed IBS status, body appreciation, body dissatisfaction, self-criticism, sociodemographic status, depression, and anxiety. Path analysis tested the hypothesized mediation model.

Results

IBS participants reported greater PD, lower body appreciation, higher body dissatisfaction, and higher self-criticism than controls. Body appreciation and self-criticism sequentially mediated the link between IBS status and both depression and anxiety. IBS was associated with reduced body appreciation, which in turn was linked to heightened self-criticism, thereby leading to elevated psychological distress.

Conclusion

Results suggest IBS negatively impacts body image appreciation, fostering self-critical judgments that exacerbate psychological symptoms. This study is the first to demonstrate a significant association between body appreciation and IBS, specifically highlighting this relationship. Findings clarify the psychosocial pathways at play in the comorbidity of mental health issues in IBS. Physicians and other health professionals are advised to detect women with IBS who are distressed, and to offer them appropriate intervention to prevent downstream consequences.

Irritable bowel syndrome (IBS): could we decide what is behind?

Functional visceral problems are frequently present nowadays in the medical practice probably due to the significant mental and emotional load on people. Although physicians and psychophysiologists are active on the field, still we are far from a complete knowledge, despite the fact that scientists like the Hungarian Professor György Ádám already had initiated a new approach called visceral psychophysiology already a long time ago. In this article, we commemorate Professor Ádám by analyzing one of the most frequent functional disorders, irritable bowel syndrome (IBS), calling psychophysiology for help. First, we try to give a definition, then show the general descriptions and characteristics of IBS. Factors like stress, gender, and gastrointestinal pain are followed by the potential role of the immune system and the neuronal factors as well as the supposed brain mechanisms. We hope that this overview of the IBS-history would show how significant scientists can be decisive in certain fields of the science and practice.

A randomized double-blind, placebo-controlled trial to evaluate the safety and efficacy of live Bifidobacterium longum CECT 7347 (ES1) and heat-treated Bifidobacterium longum CECT 7347 (HT-ES1) in participants with diarrhea-predominant irritable bowel syndrome

To determine the efficacy of the probiotic Bifidobacterium longum CECT 7347 (ES1) and postbiotic heat-treated Bifidobacterium longum CECT 7347 (HT-ES1) in improving symptom severity in adults with diarrhea-predominant irritable bowel syndrome (IBS-D), a randomised, double-blind, placebo-controlled trial with 200 participants split into three groups was carried out. Two capsules of either ES1, HT-ES1 or placebo were administered orally, once daily, for 84 days (12 weeks). The primary outcome was change in total IBS-Symptom Severity Scale (IBS-SSS) score from baseline, compared to placebo. Secondary outcome measures were stool consistency, quality of life, abdominal pain severity and anxiety scores. Safety parameters and adverse events were also monitored. The change in IBS-SSS scores from baseline compared to placebo, reached significance in the ES1 and HT-ES1 group, on Days 28, 56 and 84. The decrease in mean IBS-SSS score from baseline to Day 84 was: ES1 (-173.70 [±75.60]) vs placebo (-60.44 [±65.5]) (p < .0001) and HT-ES1 (-177.60 [±79.32]) vs placebo (-60.44 [±65.5]) (p < .0001). Secondary outcomes included changes in IBS-QoL, APS-NRS, stool consistency and STAI-S and STAI-T scores, with changes from baseline to Day 84 being significant in ES1 and HT-ES1 groups, compared to the placebo group. Both ES1 and HT-ES1 were effective in reducing IBS-D symptom severity, as evaluated by measures such as IBS-SSS, IBS-QoL, APS-NRS, stool consistency, and STAI, in comparison to the placebo. These results are both statistically significant and clinically meaningful, representing, to the best of the authors' knowledge, the first positive results observed for either a probiotic or postbiotic from the same strain, in this particular population.

Association of low occlusal force as an oral hypofunction with the prevalence of irritable bowel syndrome in Japanese adults

BACKGROUND AND AIM

We investigated whether oral-dental conditions may be associated with the prevalence of irritable bowel syndrome (IBS) in a cross-sectional study in Japan.

METHODS

Information on lifestyle and abdominal symptoms was collected, and oral-dental examinations were performed from 2013 to 2017. To investigate the association between oral-dental conditions and IBS, this study used logistic regression analyses adjusted for relevant confounding factors, such as age, sex, BMI, stress, and eating between meals.

RESULTS

The prevalence of IBS was 484 (13.4%) among 3626 participants. The mean maximum occlusal force in the IBS group was significantly lower than that in the non-IBS group (0.306 ± 0.192 kN vs. 0.329 ± 0.205 kN, P = 0.014). The maximum occlusal force of the constipation-type IBS was significantly lower than that of other types of IBS without constipation type (0.269 ± 0.164 kN vs. 0.317 ± 0.198 kN, P = 0.010). Compared with those who had high values of maximum occlusal force (≧0.265 kN), those with a low value of maximum occlusal force (<0.265 kN) had a significantly greater risk for IBS (OR, 1.426; 95% CI, 1.135-1.792; P = 0.002), by multivariate analyses, across different categories of oral-dental condition in women, not in men. Women who had lowest third occlusal force (<0.206 kN) had approximately 35% significantly greater odds of having IBS compared with those who had highest third occlusal force (≧0.386 kN).

CONCLUSIONS

Results suggest that a reduction in the maximum occlusal force increases the risk of IBS in Japanese women.

The Effect of Vitamin D Supplementation on the Severity of Symptoms and the Quality of Life in Irritable Bowel Syndrome Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Irritable bowel syndrome (IBS), a gastrointestinal disorder affecting 7-12% of the population, is characterized by abdominal pain, bloating, and alternating bowel patterns. Data on risk and protective influences have yielded conflicting evidence on the effects of alternative interventions, such as vitamin D. This review focuses on the effects of vitamin D on IBS. A systematic review and meta-analysis considered all articles published until 4 April 2022. The search for randomized controlled trials assessing vitamin D efficacy in IBS with outcomes, primary (Irritable Bowel Severity Scoring System (IBS-SSS)) and secondary (IBS quality of life (IBS-QoL) and serum level of calcifediol (25(OH)D)), was performed on six databases, Google Scholar, Web of Science, SCOPUS, EMBASE, PubMed (MEDLINE), and Cochrane Central Register of Controlled Trials. We included six trials with 616 patients. The pooled analysis found no difference between vitamin D and placebo in improving IBS-SSS (MD: -45.82 with 95% CI [-93.62, 1.98], p = 0.06). However, the pooled analysis favored vitamin D over placebo in improving the IBS-Qol (MD: 6.19 with 95% CI [0.35, 12.03], p = 0.04) and serum 25(OH)D (MD: 25.2 with 95% CI [18.41, 31.98], p = 0.00001). Therefore, further clinical trials are required to reach clinically applicable and generalizable findings.

A neuropsychosocial signature predicts longitudinal symptom changes in women with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common disorder of brain-gut interactions characterized by chronic abdominal pain, altered bowel movements, often accompanied by somatic and psychiatric comorbidities. We aimed to test the hypothesis that a baseline phenotype composed of multi-modal neuroimaging and clinical features predicts clinical improvement on the IBS Symptom Severity Scale (IBS-SSS) at 3 and 12 months without any targeted intervention. Female participants (N = 60) were identified as "improvers" (50-point decrease on IBS-SSS from baseline) or "non-improvers." Data integration analysis using latent components (DIABLO) was applied to a training and test dataset to determine whether a limited number of sets of multiple correlated baseline'omics data types, including brain morphometry, anatomical connectivity, resting-state functional connectivity, and clinical features could accurately predict improver status. The derived predictive models predicted improvement status at 3-months and 12-months with 91% and 83% accuracy, respectively. Across both time points, non-improvers were classified as having greater correlated morphometry, anatomical connectivity and resting-state functional connectivity characteristics within salience and sensorimotor networks associated with greater pain unpleasantness, but lower default mode network integrity and connectivity. This suggests that non-improvers have a greater engagement of attentional systems to perseverate on painful visceral stimuli, predicting IBS exacerbation. The ability of baseline multimodal brain-clinical signatures to predict symptom trajectories may have implications in guiding integrative treatment in the age of precision medicine, such as treatments targeted at changing attentional systems such as mindfulness or cognitive behavioral therapy.

A Low-FODMAP Diet Improves the Global Symptoms and Bowel Habits of Adult IBS Patients: A Systematic Review and Meta-Analysis

Background: A low-fermentable oligo-, di-, monosaccharides, and polyols (FODMAP) diet has been reported to be associated with improving the symptoms of irritable bowel syndrome (IBS); however, its efficacy as evaluated by different studies remains controversial. Objective: A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to explore the efficacy of a low-FODMAP diet (LFD) in alleviating the symptoms of IBS. Methods: A search of the literature for RCTs that assessed the efficacy of an LFD in treating IBS patients was conducted using the electronic databases PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science. The searches in each database were conducted from the inception of the database to February 2021. Two independent reviewers screened citations and a third reviewer resolved disagreements. Two independent reviewers also performed eligibility assessments and data extraction. The RCTs that evaluated LFDs vs. a normal IBS or usual diet and assessed changes of IBS symptoms were included in the search. Data were synthesized as the relative risk of global symptoms improvement, mean difference of IBS Severity Scoring System (IBS-SSS) score, sub-items of IBS-SSS irritable bowel syndrome-related quality of life (IBS-QOL), hospital anxiety and depression scale (HADS), stool consistency/frequency, and body mass index (BMI) using a random effects model. The risk of bias was assessed using Risk of Bias Tool 2 (RoB 2). The bias of publication was assessed based on Egger's regression analysis. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Results: A total of 2,768 citations were identified. After full-text screening, a total of 10 studies were eligible for the systematic review and were subsequently used to compare an LFD with various control interventions in 511 participants. An LFD was associated with the improvement of global symptoms [n = 420; Risk Ratio (RR) = 1.54; 95% Confidence Interval (CI) 1.18 to 2; I 2 = 38%], improvement of stool consistency [n = 434; Mean difference (MD) = -0.25; 95% CI -0.44 to -0.06; I 2= 19%), and a reduction trend of stool frequency (n = 434; MD = -0.28; 95% CI -0.57 to 0.01; I 2 = 68%) compared with control interventions. There was no statistically significant change in IBS-QOL (n = 484; MD = 2.77; 95% CI -2 to 7.55; I 2 = 62%), anxiety score (n = 150; MD = -0.45; 95% CI -3.38 to 2.49; I 2 = 86%), depression score (n = 150; MD = -0.05; 95% CI -2.5 to 2.4; I 2 = 88%), and BMI (n = 110; MD = -0.22; 95% CI -1.89 to 1.45; I 2 = 14%). The overall quality of the data was "moderate" for "global improvement of IBS symptom," "stool consistency," "stool consistency for IBS with diarrhea (IBS-D)," and "stool frequency for IBS-D," and "low" or "very low" for other outcomes according to GRADE criteria. Conclusion: An LFD is effective in reducing the global symptoms and improving the bowel habits of adult IBS patients. The efficacy for IBS-D patients can also be more pronounced. Systematic Review Registration: CRD42021235843.

Ameliorating effects and mechanisms of transcutaneous auricular vagal nerve stimulation on abdominal pain and constipation

BackgroundAbdominal pain and constipation are 2 main symptoms in patients with constipation-predominant irritable bowel syndrome (IBS-C). This study aimed to investigate the effects and possible mechanisms of transcutaneous auricular vagal nerve stimulation (taVNS) in patients with IBS-C.MethodsForty-two patients with IBS-C were randomized into a 4-week sham-taVNS or taVNS treatment. The primary outcomes were complete spontaneous bowel movements per week (CSBMs/week) and visual analog scale (VAS) for abdominal pain. High-resolution anorectal manometry (HRAM) was performed to evaluate anorectal motor and sensory function. Cytokines and brain gut peptides were analyzed in blood samples. ECG was recorded for the assessment of autonomic function.ResultsCompared with sham-taVNS, (a) taVNS increased CSBMs/week (P = 0.001) and decreased VAS pain score (P = 0.001); (b) improved quality of life (P = 0.020) and decreased IBS symptom score (P = 0.001); (c) improved rectoanal inhibitory reflex (P = 0.014) and improved rectal sensation (P < 0.04); (d) decreased a number of proinflammatory cytokines and serotonin in circulation; and (e) enhanced vagal activity (P = 0.040). The vagal activity was weakly correlated with the CSBMs/week (r = 0.391; P = 0.010) and the VAS pain score (r = -0.347; P = 0.025).ConclusionsNoninvasive taVNS improves both constipation and abdominal pain in patients with IBS-C. The improvement in IBS-C symptoms might be attributed to the integrative effects of taVNS on intestinal functions mediated via the autoimmune mechanisms.Trial registrationwww.chictr.org.cn, no. ChiCTR2000029644.FundingNational Natural Science Foundation of China (grant no. 81970538 for FL).

Modified colonic transit test in healthy subjects and constipated patients: A triple-phase, two-center prospective study

BACKGROUND AND AIM

Classic daily-ingestion single-film protocol using radiopaque markers for colonic transit time (CTT) is unsuitable for Chinese patients because of rapid colonic motility. A new modified method needs to be established.

METHODS

The triple-phase study was performed. In Phase I, the classic protocol was assessed to evaluate its feasibility for Chinese subjects. In Phase II, a modified protocol was performed in two centers on 180 healthy subjects and 90 constipated patients to determine optimal conditions. In Phase III, the simplified protocol was validated on 90 constipated patients.

RESULTS

All the subjects of the Phase I expelled more than 95% of the markers during the examination period, which means that the classic protocol is unsuitable for Chinese patients. The 20.9-h mean total CTT for healthy Chinese subjects was much faster than that seen in Western countries. As shown by Phase II, the numbers of subjects went beyond the upper limit were 22 in P1TCTT and 10 in P2TCTT (8.14% vs 3.70%, P = 0.029). The percentage of values fall outside of the measurement range of excretion ratio was around half of our study subjects (45-70%), whereas this percentage was only 3.70% using P2TCTT. The simplified protocol had a diagnostic accuracy for constipation of 0.81, with a sensitivity and specificity of 0.46 and 0.97, respectively.

CONCLUSIONS

Colon movement in Chinese individuals is significantly faster than that of Western populations. The modified protocol generated in this study is appropriate for diagnosis of constipation in population with rapid colon motility.

Evidence-based clinical practice guidelines for irritable bowel syndrome 2020

Managing irritable bowel syndrome (IBS) has attracted international attention because single-agent therapy rarely relieves bothersome symptoms for all patients. The Japanese Society of Gastroenterology (JSGE) published the first edition of evidence-based clinical practice guidelines for IBS in 2015. Much more evidence has accumulated since then, and new pharmacological agents and non-pharmacological methods have been developed. Here, we report the second edition of the JSGE-IBS guidelines comprising 41 questions including 12 background questions on epidemiology, pathophysiology, and diagnostic criteria, 26 clinical questions on diagnosis and treatment, and 3 questions on future research. For each question, statements with or without recommendations and/or evidence level are given and updated diagnostic and therapeutic algorithms are provided based on new evidence. Algorithms for diagnosis are requisite for patients with chronic abdominal pain or associated symptoms and/or abnormal bowel movement. Colonoscopy is indicated for patients with one or more alarm symptoms/signs, risk factors, and/or abnormal routine examination results. The diagnosis is based on the Rome IV criteria. Step 1 therapy consists of diet therapy, behavioral modification, and gut-targeted pharmacotherapy for 4 weeks. For non-responders, management proceeds to step 2 therapy, which includes a combination of different mechanistic gut-targeted agents and/or psychopharmacological agents and basic psychotherapy for 4 weeks. Step 3 therapy is for non-responders to step 2 and comprises a combination of gut-targeted pharmacotherapy, psychopharmacological treatments, and/or specific psychotherapy. These updated JSGE-IBS guidelines present best practice strategies for IBS patients in Japan and we believe these core strategies can be useful for IBS diagnosis and treatment globally.

Irritable Bowel Syndrome: News from an Old Disorder

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder, which can affect all members of a society, regardless of age, sex, race or socioeconomic status. Because of its high prevalence and chronic nature, it represents a significant economic burden. In fact, these patients have a relevant impairment of their quality of life, which limits their work productivity and daily social activities, especially when it is associated with other disorders, such as anxiety and depression. The diagnosis of IBS relies on symptom-based diagnostic criteria with normal results on a limited number of complementary tests that rule out other possible diagnoses. The aetiology of this condition is incompletely established. However, evidence suggests that it is a multifactorial disorder with several different mechanisms that have been implicated as responsible for the symptoms. Since the treatment strategy is usually based on predominant symptoms and their severity, it is important to recognise the underlying mechanisms in order to successfully relief the visceral pain and altered bowel habits. The aim of this non-systematic review of the literature was to explore the pathophysiology and treatment options of IBS, highlighting the most recent evidence, from the new Rome IV criteria to the new drug armamentarium.

Adherence to the pro-inflammatory diet in relation to prevalence of irritable bowel syndrome

Objective

There is no prior study that examined the association between nutrient-based dietary inflammatory index (DII) and odds of Irritable Bowel Syndrome (IBS). We examined the association between DII score and odds of IBS and its severity among Iranian adults.

Methods

In this cross-sectional study, dietary intakes of 3363 Iranian adults were examined using a validated Dish-based 106-item Semi-quantitative Food Frequency Questionnaire (DS-FFQ). DII was calculated based on dietary intakes derived from DS-FFQ. IBS was assessed using a modified Persian version of Rome III questionnaire.

Results

After adjustment for potential confounders, we found that participants in the highest quintile of DII score had greater chance for IBS compared with those in the lowest quintile (OR: 1.36; 95% CI: 1.03–1.80). By gender, we found a significant association between DII score and IBS among women (OR: 1.41; 95% CI: 1.00–2.00). By BMI status, overweight or obese (BMI ≥ 25 kg/m²) individuals in top quintile of DII score had greater odds for IBS than those in the bottom quintile (OR: 1.64; 95% CI: 1.07–2.53). No significant association was observed between a pro-inflammatory diet and severity of IBS symptoms.

Conclusions

Consumption of a pro-inflammatory diet was associated with increased odds of IBS, in particular among women and those with BMI ≥ 25 kg/m².

ANALYSIS OF LACTOSE INTOLERANCE IN STUDENTS WITH SUGGESTIVE SYMPTOMS OF IRRITABLE BOWEL SYNDROME

BACKGROUND

Irritable bowel syndrome is a clinical condition presenting pain, distension and abdominal fullness, diarrhea, constipation, and other symptoms. It generates significant impacts on the quality of life of those affected. The pathophysiology is uncertain, but the role of various food types has been established in bowel sensitivity and its clinical manifestations. Carbohydrate intolerance, particularly to lactose, generates similar and sometimes indistinguishable symptoms from irritable bowel syndrome, and in clinical practice is both a frequent and underdiagnosed condition. Carbohydrate intolerance is related to enzymatic deficiencies, alterations of intestinal microbiota and even genetic change. The principal test for a diagnosis of lactose intolerance is the breath test, which measures hydrogen emission (produced only by bacteria), after ingestion of the corresponding substrate.

OBJECTIVE

The present work aims to verify the prevalence of lactose intolerance in university students, presenting gastrointestinal symptoms suggestive of irritable bowel syndrome.

METHODS

In a transversal study, to screen for those with suggestive symptoms, 124 medicine students participated by responding to a form. Those with abdominal pain were referred for anti-parasite treatment in order to exclude intestinal parasites as a secondary cause. Subsequently, using the hydrogen breath test, bacterial overgrowth was investigated, and if negative, lactose intolerance testing would be performed. Patients presenting high hydrogen concentrations of ≥20 ppm above the basal level were considered lactose intolerant.

RESULTS

Of the total of students researched (n=124), 7 were excluded because they did not completing all study phases. From those 117 individuals effectively included in the survey; 8 (6.8%) were diagnosed with lactose intolerance and 2 (1.7%) with bacterial overgrowth. Intolerance was more frequent in; female individuals (75%), age range 18 to 25 years (62.5%), being colored (50%), and in their 5th semester of studies (37.5%). The presence of at least one gastrointestinal symptom among those presenting intolerance (100%), and those not presenting intolerance (42.2%) was found (P=0.002). In addition to abdominal pain (100%) (P<0.001), the most recurrent gastrointestinal symptom in the lactose intolerant students was the distension/flatulence (62.5%) (P=0.026). In relation to life habits and food patterns, there was no statistical difference between lactose tolerant and intolerant individuals, or for symptom frequencies. The more advanced students, completing more periods towards graduation, demonstrated more occurrences of gastrointestinal symptoms, yet without presenting significant statistical discrepancies.

CONCLUSION

In view of the test sample quantity (n=21), a high prevalence of lactose intolerance (6.8%) in the academic environment, with epidemiological characteristics compatible to those found the literature is demonstrated, generating knowledge with understanding to prevent, diagnose, alleviate and treat lactose intolerant university students, and generate positive impacts towards well-being, improving the quality of life of these individuals.

Inhibition of CFTR-mediated intestinal chloride secretion as potential therapy for bile acid diarrhea

Bile acid diarrhea (BAD) is common with ileal resection, Crohn's disease, and diarrhea-predominant irritable bowel syndrome. Here, we demonstrate the efficacy of cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor (R)-benzopyrimido-pyrrolo-oxazine-dione-27 (BPO-27) in reducing bile acid-induced fluid and electrolyte secretion in colon. Short-circuit current measurements in human T84 colonic epithelial cells and planar colonic enteroid cultures showed a robust secretory response following mucosal but not serosal addition of chenodeoxycholic acid (CDCA) or its taurine conjugate, which was fully blocked by CFTR inhibitors, including (R)-BPO-27. (R)-BPO-27 also fully blocked CDCA-induced secretory current in murine colon. CFTR activation by CDCA primarily involved Ca2+ signaling. In closed colonic loops in vivo, luminal CDCA produced a robust secretory response, which was reduced by ∼70% by (R)-BPO-27 or in CFTR-deficient mice. In a rat model of BAD produced by intracolonic infusion of CDCA, (R)-BPO-27 reduced the elevation in stool water content by >55%. These results implicate CFTR activation in the colon as a major prosecretory mechanism of CDCA, a bile acid implicated in BAD, and support the potential therapeutic efficacy of CFTR inhibition in bile acid-associated diarrheas.-Duan, T., Cil, O., Tse, C. M., Sarker, R., Lin, R., Donowitz, M., Verkman, A. S. Inhibition of CFTR-mediated intestinal chloride secretion as potential therapy for bile acid diarrhea.

EVALUATION OF CARBOHYDRATE AND FIBER CONSUMPTION IN PATIENTS WITH IRRITABLE BOWEL SYNDROME IN OUTPATIENT TREATMENT

BACKGROUND

Irritable bowel syndrome (IBS) is a chronic functional condition, which main symptoms of pain, discomfort and abdominal distension, constipation, diarrhea, altered fecal consistency and sensation of incomplete evacuation can be influenced by the presence of dietary fiber and fermentable carbohydrates (FODMAPs). This study aimed to assess the relationship between the quantity of fermentable carbohydrates (FODMAP) and fiber consumed by individuals diagnosed with IBS, and their classification according to the Rome III criteria.

METHODS

A transversal study was carried out in the Intestinal Outpatient Clinic of the Gastroenterology Discipline of UNIFESP. The nutrients of interest for the study were: fiber, general carbohydrates and FODMAPs, with intake quantity measured in grams, analyzed through portions consumed. A nutrition log was used, along with a semi-quantitative questionnaire of consumption frequency.

RESULTS

The sample included 63 adult patients; 21 with constipated IBS, 21 with diarrhea IBS, and 21 with mixed IBS. Carbohydrate intake was suboptimal in 55.6% of patients in all groups; excessive consumption was identified in 38.1% of the diarrhea group, 14.3% of the mixed group and 38.1% of the constipated group. Low consumption of carbohydrates was found in 28.6% of diarrhea patients and 47.6% of the mixed group. A mean intake of 23 g of fiber per day was identified, lower than recommended.

CONCLUSION

The study identified a number of inadequacies in the consumption of different nutrients, excessive carbohydrate intake, especially FODMAPs, identified by the respondents as responsible for a worsening of their conditions. By contrast, other food groups such as meat, eggs and dairy were consumed by the sample population in insufficient quantities.

Empirically derived food-based inflammatory potential of the diet, irritable bowel syndrome, and its severity

OBJECTIVE

To our knowledge, no studies have examined the association between the empirically derived food-based dietary inflammatory index (FDII) and irritable bowel syndrome (IBS). The aim of this study was to examine the relationship between the FDII score and IBS in a large sample of Iranian adults.

METHODS

In this cross-sectional study, the dietary intakes of 3363 adults were assessed using a validated dish-based 106-item semi-quantitative food frequency questionnaire (DS-FFQ). The FDII was calculated based on the dietary intakes of food groups derived from DS-FFQ. IBS was assessed using a modified Persian version of the Rome III questionnaire.

RESULTS

Participants in the top quintile of the FDII score had a 42% greater risk for IBS than those in the bottom quintile (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.08-1.88). Among women, we observed a significant direct association between the FDII score and IBS after adjustment for potential confounders (OR, 1.44; 95% CI, 1.01-2.04). By body mass index (BMI) status, normal weight subjects (BMI <25 kg/m²) in the top quintile of the FDII score had higher risk for IBS (OR, 1.60; 95% CI, 1.07-2.35) than those in the bottom quintile. These associations were not observed in men or in participants with a BMI ≥25 kg/m². There was no significant association between the FDII score and IBS subtypes. No significant association between the FDII score and IBS severity was observed.

CONCLUSIONS

Consumption of a pro-inflammatory diet was associated with increased risk for IBS, especially in women and in individuals with a BMI <25 kg/m².

Association of irritable bowel syndrome and venous thromboembolism

OBJECTIVE

Inflammatory bowel disease (IBD) is associated with venous thromboembolism (VTE). Whether functional gastrointestinal disorders, such as irritable bowel syndrome (IBS), are associated with VTE has not been determined. This nationwide study aimed to determine the risk of VTE in IBS outpatients in primary and specialist care.

DESIGN

We performed two matched case-control studies. Cases (n = 90,502) were individuals in Sweden aged 18-80 years with a first hospital diagnosis of VTE between 2001 and 2010. Five controls (n = 452,510) from the Swedish Total Population Register were matched to each case for birth, sex, country of birth, and education level. Diagnosis of IBS was determined in the Swedish hospital outpatient register. This procedure was replicated for the primary care population. As the Primary Care data did not have nationwide coverage, we only included individuals that were registered in the Primary Care database. A total of 9766 cases of hospital diagnosed VTE individuals could be found in the Primary Care population and they were matched to 48,830 controls also from the Primary health care population. Conditional logistic regression was used to determine odds ratio (OR) for first VTE diagnosis. Results The adjusted OR for VTE when IBS was diagnosed in hospital outpatient care was 1.49 (95% confidence interval 1.33-1.67). The crude OR for VTE was 1.18 (0.94-1.48) when IBS was diagnosed in primary care.

CONCLUSIONS

This is the first study describing an association between VTE and IBS. The results suggest that specialist treated IBS patients have increased risk of VTE.

Translocator protein 18kDa antagonist ameliorates stress-induced stool abnormality and abdominal pain in rodent stress models

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder characterized by abdominal pain and abnormal bowel habits, both of which are exacerbated by psychological stress. The translocator protein 18kDa (TSPO) is a marker of reactive gliosis in a number of central nervous system (CNS) diseases and responsible for many cellular functions, including neurosteroidogenesis. Although it has been reported that psychological stress disturbs neurosteroids levels, the pathophysiological relevance of TSPO in IBS is poorly understood.

METHODS

We examined the effects of a TSPO antagonist, ONO-2952, on stress-induced stool abnormality and abdominal pain in rats, and on anxiety-related behavior induced by cholecystokinin.

KEY RESULTS

Oral administration of ONO-2952 attenuated stress-induced defecation and rectal hyperalgesia in rats with an efficacy equivalent to that of a 5-HT₃ receptor antagonist. In addition, ONO-2952 suppressed cholecystokinin-induced anxiety-like behavior with an efficacy equivalent to that of psychotropic drugs. On the other hand, ONO-2952 did not affect spontaneous defecation, gastrointestinal transit, visceral nociceptive threshold, and neurosteroid production in non-stressed rats even at a dose 10 times higher than its effective dose in the stress models.

CONCLUSIONS AND INFERENCES

These results suggest that TSPO antagonism results in antistress action, and that ONO-2952 is a promising candidate for IBS without side effects associated with current treatment.

Health education program improves QOL in students with irritable bowel syndrome after the Wenchuan earthquake: a five-year multi-center study

Background

Stress is a common contributing factor for irritable bowel syndrome (IBS). This study was to evaluate the efficacy of the centralized health education program in improving the quality of life (QOL) of middle school students with IBS who experienced the Wenchuan earthquake on May 12, 2008.

Methods

A multi-center, randomized and open evaluation study design was adopted. A total of 584 students who met the Rome III criteria for IBS in four middle schools were identified. Of these students, 29 were excluded for various reasons, and the remaining 555 students were randomly assigned to either the health education group (n = 277) or the control group (n = 278, received no health education). De-identified data were collected via the IBS quality of life (IBS-QOL) questionnaire and abdominal pain was assessed during the 5-year follow-up survey.

Results

The IBS-QOL mean total score was comparable at baseline between no-education group and education group no matter in quake-unaffected areas or quake-affected areas (52.27 vs 51.43, t = 1.15, P > 0.05; 51.02 vs 50.64, t = 1.98, P > 0.05). During the 5-year study period, 84 students opted out during follow-up. After 5 years, a significant difference of the IBS-QOL mean total score was observed between the no-education group and education group in quake-unaffected areas (80.53 vs 93.67, t = − 55.45, P < 0.01), which was also observed in quake-affected areas (64.23 vs 93.80, t = − 188.10, P < 0.01). In addition, there was a reciprocal action between factor 1(health education or not) and factor 2(affected by the earthquake or not) regarding IBS-QOL for dysphoria(Q1), interference with activity(Q2), food avoidance(Q5) and relationships(Q8)(P < 0.001) at year 1, 3 and 5. In all students, abdominal pain scores gradually reduced from baseline in each subgroup over 5 years (P < 0.001).The improvement was greater in the education group than in the control group no matter in quake-unaffected area and in quake-affected areas(P < 0.001). There was a reciprocal action between factor 1(health education or not) and factor 2(duration of follow-up) regarding the mean abdominal pain symptom score irrespective of quake-unaffected or quake-affected areas (P = 0.029 and P < 0.001).

Conclusion

The health education program improved quality of life and abdominal pain in middle school IBS students in Wenchuan quake-affected areas.

Blastocystis subtypes and their association with Irritable Bowel Syndrome

Blastocystis spp. is a common intestinal protozoan that affects humans and animals. The role of this parasite as a pathogen is still controversial and it is suspected to be linked to Irritable Bowel Syndrome (IBS), a functional bowel disorder characterized by chronic or recurrent abdominal pain associated with altered intestinal habits. A broad search in electronic databases, libraries, portals of journals, etc. for reports on the association between the parasite and IBS without language restriction was performed. The selection was not restricted by date, but articles published in the last seven years were given preference. We investigated the evidence regarding Blastocystis and IBS coexistence as well as the implications of the parasite in pathogenesis and clinical manifestations. Only standardized parasitological tools, supplemented by epidemiological analysis, will be able to clarify whether parasite carriage could be connected to IBS and its status as a human pathogen. Although a variation in pathogenicity and virulence between subtypes has been confirmed, Blastocystis can only be considered an indicator of dysbiosis. Accurate diagnoses of this parasitic eukaryote, specifically at genotypic and phenotypic levels, as well as the complete analysis of the intestinal microbial communities, have to be included in the protocol of those patients with IBS.

Pilot-RCT of an integrative group therapy for patients with refractory irritable bowel syndrome (ISRCTN02977330)

OBJECTIVE

Different forms of psychotherapeutic treatments have been proven effective in irritable bowel syndrome (IBS), but disorder-oriented and integrative concepts are still rare. Therefore, we implemented and evaluated an integrative group therapeutic concept within an interdisciplinary tertiary care clinic for functional gastrointestinal disorders (FGIDs).

AIMS

present our integrative group concept, assess feasibility issues, and evaluate efficacy.

METHODS

A pilot-RCT with a randomized controlled wait-listed group design was conducted. The treatment concept was a disorder-oriented multicomponent group therapy (12 90-min weekly sessions) integrating interactive psychoeducation, gut-directed hypnotherapy, and open group phases. All patients received enhanced medical care and completed a short online diary as an active wait-listed control condition.

INCLUSION CRITERIA

refractory IBS diagnosed as somatoform autonomic dysfunction of the lower gastrointestinal tract (SAD).

PRIMARY OUTCOME

IBS symptom severity (IBS-SSS).

RESULTS

Of 294 patients, 220 had IBS (ROME III), 144 were diagnosed as SAD (ICD-10), 51 were eligible regarding inclusion/exclusion criteria, and 30 consented to participate (group intervention: n=16, wait-listed control condition: n=14). Only 1 patient dropped out. Intention-to-treat-analysis with repeated-measures mixed ANOVA showed that the group intervention was not significantly superior to the wait-listed control condition. Nevertheless, the calculated effect size for the between-group difference in IBS-SSS at the end of treatment (post) was moderate (d=0.539).

CONCLUSION

Our disorder-oriented integrative group intervention for IBS proved to be acceptable and feasible in an interdisciplinary tertiary care setting. There is promise in this intervention, but a larger RCT may be needed to investigate efficacy.

Dietary behaviors in relation to prevalence of irritable bowel syndrome in adolescent girls

BACKGROUNDS AND AIMS

There is limited evidence regarding the relationship between dietary behaviors and irritable bowel syndrome (IBS). This study aimed to explore the association between diet-related practices and prevalence of IBS.

METHODS

The study was conducted among 988 adolescent girls living in Iran. Dietary behaviors were pre-defined and assessed in nine domains using a pre-tested questionnaire. To investigate the association between diet-related practices and the presence of IBS, this study used logistic regression analysis in crude and adjusted models.

RESULTS

The prevalence of IBS was 16.9% in this population. Compared with individuals who did not consume fluid with their meal, those who always consumed fluid with meals had a greater chance of IBS (odds ratio [OR]: 2.91; P: 0.01). This study found a direct relationship between a greater intake of spicy food and IBS prevalence (OR: 5.28; P: 0.02). The individuals who ate fried foods every day also had a greater risk of IBS compared with those who did not consume fried foods (OR: 1.65; P: 0.01). The subjects who had lost ≥ 5 teeth had 2.23 times greater odds for IBS than the individual who had lost ≤ 1 tooth (OR: 2.23; P: 0.01) was a significant inverse relationship between the chewing sufficiency and the risk of IBS (OR: 4.04; P: 0.02). These associations remained significant after controlling for potential confounder.

CONCLUSIONS

Intra-meal fluid intake, chewing insufficiency, higher tooth loss, and the consumption of spicy and fried food were associated with increased risk of IBS. Prospective studies are needed to confirm these findings.

Fatty acid components in Asian female patients with irritable bowel syndrome

Abdominal pain is one of the key symptoms of irritable bowel syndrome (IBS). Studies have indicated an increase in the incidence of IBS in Asia. However, yet the pathophysiology of this disease remains unknown. Women are more likely to develop the condition than men, especially the constipation-predominant type. Essential fatty acid (EFA) malnutrition is one of several theories discussing the mechanism of IBS.The authors hypothesized that significant EFA deficiency may cause abdominal pain in patients with IBS. However, because patterns in the oral intake of EFAs differ between cultures, the authors narrowed this study to examine the nutritional status of Asian female patients with IBSThe authors investigated Asian female patients with IBS and compared them with a group of healthy controls. Thirty patients with IBS and 39 healthy individuals were included in this study. The participants' age, height, weight, and waist size were recorded. The 24-item Hamilton Depression Rating Scale was documented. Both erythrocyte and plasma fatty acid content were analyzed through gas-liquid chromatography.The authors found that patients with IBS exhibited significantly higher scores for depression, higher proportions of plasma saturated fatty acids and monounsaturated fatty acids, and lower proportions of docosahexaenoic acid and total omega-3 polyunsaturated fatty acids in plasma are associated with IBS in Asian female patients. Further study is indicated to confirm the causality of this association.

A Swedish national adoption study of risk of irritable bowel syndrome (IBS)

Objectives

Irritable bowel syndrome (IBS) clusters in families, but the familial risk of IBS has not been determined in adoptees. Studying adoptees and their biological and adoptive parents is a strong study design for separating genetic from environmental causes of familial clustering. This nationwide study aimed to separate the biological (genetic) and familial environmental contribution to the familial transmission of IBS.

Methods

We performed a family study for Swedish-born adoptees born from 1951 until 1995, and their biological and adoptive parents. The Swedish Multigeneration Register was linked to the Hospital Register (inpatients and outpatients) for the period 1964-2012 and the Swedish Outpatient Care Register for 2001-2012, and the Swedish Primary Healthcare register for 1989-2012. ORs for IBS were calculated for adoptees with an affected biological parent with IBS compared with adoptees without a biological parent with IBS. The OR for IBS was also determined in adoptees with an adoptive parent with IBS compared with adoptees without an adoptive parent with IBS. Heritability h² (±SE) was also determined.

Results

The ORs for IBS were 1.67 in adoptees (95% CI 1.06 to 2.62) of biological parents diagnosed with IBS. The ORs for IBS were 0.88 in adoptees (95% CI 0.48 to 1.63) of adoptive parents diagnosed with IBS. The heritability was 19.5%±8.5%.

Conclusions

The present study indicates that biological (genetic) factors are important for the familial clustering of IBS. The heritability calculated is in the range from twin studies and suggests that heritability may be estimated in adoptees.

Negative correlation of cortical thickness with the severity and duration of abdominal pain in Asian women with irritable bowel syndrome

Background & aims

Irritable bowel syndrome (IBS) manifests as chronic abdominal pain. One pathophysiological theory states that the brain–gut axis is responsible for pain control in the intestine. Although several studies have discussed the structural changes in the brain of IBS patients, most of these studies have been conducted in Western populations. Different cultures and sexes experience different pain sensations and have different pain responses. Accordingly, we aimed to identify the specific changes in the cortical thickness of Asian women with IBS and to compare these data to those of non-Asian women with IBS.

Methods

Thirty Asian female IBS patients (IBS group) and 39 healthy individuals (control group) were included in this study. Brain structural magnetic resonance imaging was performed. We used FreeSurfer to analyze the differences in the cortical thickness and their correlations with patient characteristics.

Results

The left cuneus, left rostral middle frontal cortex, left supramarginal cortex, right caudal anterior cingulate cortex, and bilateral insula exhibited cortical thinning in the IBS group compared with those in the controls. Furthermore, the brain cortical thickness correlated negatively the severity as well as duration of abdominal pain.

Conclusions

Some of our findings differ from those of Western studies. In our study, all of the significant brain regions in the IBS group exhibited cortical thinning compared with those in the controls. The differences in cortical thickness between the IBS patients and controls may provide useful information to facilitate regulating abdominal pain in IBS patients. These findings offer insights into the association of different cultures and sexes with differences in cortical thinning in patients with IBS.

Comparison of Symptoms, Healthcare Utilization, and Treatment in Diagnosed and Undiagnosed Individuals With Diarrhea-Predominant Irritable Bowel Syndrome

OBJECTIVES

Irritable bowel syndrome (IBS) is a functional bowel disorder characterized by symptoms including abdominal pain and altered bowel function. Up to 75% of individuals with IBS may be undiagnosed. The aim of this study was to characterize symptoms, healthcare utilization, and treatments in populations with both diagnosed and undiagnosed IBS.

METHODS

An online survey was conducted to compare gastrointestinal (GI) symptoms, healthcare visits, well-being, symptom management, and treatment satisfaction in individuals with and without medically diagnosed IBS (Rome III criteria). Symptom severity, disruptiveness, and treatment satisfaction were rated using a 7-point scale. Adjustments to daily life were determined by predefined survey responses.

RESULTS

A total of 1,924 individuals with a history of GI symptoms were eligible and completed the survey. Of these, 1,094 individuals (56.9%) met the criteria for IBS; 830 individuals (43.1%) had no medical diagnosis of IBS despite meeting diagnostic criteria. Most participants received a diagnosis from either gastroenterologists (45%) or primary care physicians (42%). A greater percentage of diagnosed patients had severe GI symptoms (score ≥6) vs. undiagnosed individuals (16% vs. 8%, respectively; P<0.05); diagnosed patients were more likely to report that GI symptoms adversely affected their quality of life. Approximately 40% of participants received IBS-related treatment from primary care physicians; 26% and 43% of diagnosed and undiagnosed individuals, respectively, were not receiving treatment for GI symptoms.

CONCLUSIONS

Many individuals with IBS-related symptoms have not been medically diagnosed with IBS. IBS-related symptoms impact quality of life, yet more than one-third of individuals are not receiving treatment for IBS.

Novel Indications for Fecal Microbial Transplantation: Update and Review of the Literature

BACKGROUND AND AIMS

Fecal microbial transplantation (FMT) is an established successful treatment modality for recurrent Clostridium difficile infection (CDI). The safety profile and potential therapeutic advantages of FMT for diseases associated with dysbiosis and immune dysfunction have led to many publications, mainly case series, and while many studies and reviews have been published on the use of FMT for inflammatory bowel disease (IBD), its potential use for other disease conditions has not been thoroughly reviewed. The aim of this review was to investigate the evidence surrounding the use of FMT in conditions other than IBD and CDI.

METHODS

A PubMed search was performed using the terms "Fecal microbiota transplantation" OR "FMT" OR "Bacteriotherapy."

RESULTS

A total of 26 articles describing the use of FMT in a variety of both intra-and extraintestinal disease conditions including gastrointestinal, hematologic, neurologic, metabolic, infectious, and autoimmune disorders have been included in this review and have demonstrated some positive results. The studies included were case reports, case series, controlled trials, and cohort studies.

CONCLUSIONS

The findings of these studies demonstrate that FMT, particularly in conditions associated with gastrointestinal dysbiosis, shows promise to provide another effective tool in the therapeutic armament of the practicing physician. FMT was found to be possibly effective in various diseases, mostly associated with enteric dysbiosis or with immune dysfunction. Randomized clinical studies on large populations should be performed to explore the effectiveness of this therapy, and basic research studies should be designed to gain understanding of the mechanisms through which impact these disorders.

Reassurance for patients with non-specific conditions - a user's guide

•

Reassurance is a frequently utilized yet poorly understood clinical skill.

•

Emotional distress is an important driver of healthcare use.

•

Diagnostic test results are not reassuring.

•

Some attempts at reassurance can increase rather than decrease concern.

•

Patient education is a promising way for clinicians to manage emotional distress.

Introduction

Reassurance is the removal of fears and concerns about illness. In practice reassurance for non-specific conditions, where a diagnosis is unclear or unavailable, is difficult and can have unexpected effects. Many clinical guidelines for non-specific conditions such as low back pain recommend reassurance. Until recently, there was little evidence on how to reassure patients effectively.

Results

High distress causes patients to consult more often for low back pain. To reduce distress, clinicians should provide structured education, which is effective in the short- and long-term. A newly developed online prognostic tool has the potential to improve the quality of reassurance and reduce the number of inappropriate interventions provided for low back pain.

Conclusion

Targeted reassurance, including enhanced, prognosis-specific education, could optimize reassurance and possibly prevent disabling symptoms.

Dietary patterns and prevalence of irritable bowel syndrome in Iranian adults

BACKGROUND

Although several dietary factors have been reported to alleviate or aggravate the symptoms of irritable bowel syndrome (IBS), no information is available linking habitual dietary patterns to irritable bowel syndrome.

OBJECTIVE

This study was undertaken to assess the association between dietary patterns and the risk of IBS among Iranian adults.

METHODS

In this cross-sectional study, data on 3846 Iranian adults working in 50 different health centers were examined. Dietary intake of study participants was assessed using a 106-item self-administered Dish-based Semi-quantitative Food Frequency Questionnaire (DS-FFQ) which was designed and validated specifically for Iranian adults. To identify major dietary patterns based on the 39 food groups, we used principal component analysis. A modified Persian version of the Rome III questionnaire was used for assessment of IBS.

RESULTS

We identified four major dietary patterns: (i) 'fast food', (ii) 'traditional', (iii) 'lacto-vegetarian', and (iv) 'western' dietary pattern. After adjustment for potential confounders, we found that those in the highest quartile of 'fast food' dietary pattern were tended to have higher risk of IBS than those in the lowest quartile (OR = 1.32; 95% CI: 0.99, 1.75, ptrend = 0.05). An inverse association was also found between 'lacto-vegetarian' dietary pattern and risk of IBS; such that even after adjustment for potential confounders, those in top quartile of this dietary pattern were 24% less likely to have IBS (0.76; 0.59, 0.98; ptrend = 0.02). No overall significant associations were observed between 'traditional' and 'western' dietary patterns and risk of IBS, either before or after adjustment for covariates.

CONCLUSION

We found that 'lacto-vegetarian' dietary pattern was associated with reduced risk, while 'fast food' dietary pattern was associated with a greater risk of IBS in Iranian adults.

Prevalence of Irritable Bowel Syndrome-like Symptoms in Japanese Patients with Inactive Inflammatory Bowel Disease

Background/Aims

Few studies are available that have investigated the risk factors for overlapping irritable bowel syndrome (IBS)-like symptoms in patients with inactive inflammatory bowel disease (IBD). The present study has 3 objectives: (1) to assess the prevalence of IBS-like symptoms in Japanese patients with inactive IBD using Rome III criteria, (2) to examine the relationship of IBS-like symptoms to health related quality of life (HR-QOL), and (3) to investigate associations for developing IBS-like symptoms in patients with inactive IBD.

Methods

IBS-like symptoms were evaluated using the Rome III questionnaire for functional gastrointestinal disorders. HR-QOL and hospital anxiety and depression scale were evaluated.

Results

IBS-like symptoms were found in 17.5% (7/40) of patients with inactive ulcerative colitis, 27.1% (29/107) of patients with inactive Crohn’s disease (CD), and 5.3% (23/438) of healthy control subjects. The QOL level was significantly lower and anxiety score was significantly higher in inactive CD patients with IBS-like symptoms than in those without such symptoms (P = 0.003, P = 0.009). Use of anti-anxiety drugs was associated with the presence of IBS symptoms (P = 0.045). HR-QOL score was lower and anxiety score was higher in patients with inactive ulcerative colitis, but the difference was not statistically significant.

Conclusions

The prevalence of IBS-like symptoms in inactive IBD patients was significantly higher than in healthy controls. Inactive CD patients with IBS-like symptoms has low QOL and anxiety; suggesting that anxiety may be associated with symptom development in such patients.

Effect of vitamin D on gastrointestinal symptoms and health-related quality of life in irritable bowel syndrome patients: a randomized double-blind clinical trial

BACKGROUND

Low-grade mucosal inflammation and immune activation are involved in the pathogenesis of irritable bowel syndrome (IBS). Furthermore, IBS symptoms are associated with a significantly higher prevalence of psychological distress, which in itself results into an impaired quality of life (QoL). Vitamin D could ameliorate the symptoms of patients suffering from IBS through its beneficial effects on psychological factors and inflammation.

METHODS

A total of 90 IBS patients participated in this double-blind, randomized, placebo-controlled study. Participants were randomly selected to receive either 50 000 IU vitamin D3 or a placebo fortnightly for a period of 6 months. Patients reported their IBS symptoms at the baseline and monthly during intervention periods. The IBS severity score system (IBSSS) and IBS-specific QoL questionnaires were used at the baseline and postintervention.

KEY RESULTS

Over the 6-month intervention period, a significantly greater improvement in IBS symptoms such as abdominal pain and distention, flatulence, rumbling, and overall gastrointestinal (GI) symptoms (except dissatisfaction with bowel habits) was observed in the patients receiving vitamin D as compared to the placebo group. The IBSSS and the IBS-QoL scores in the vitamin D group significantly improved compared to the placebo group postintervention (mean IBSSS score change: -53.82 ± 23.3 vs -16.85 ± 25.01, p < 0.001, respectively; mean IBS-QoL score change: 14.26 ± 3 vs 11 ± 2.34, p < 0.001, respectively).

CONCLUSIONS & INFERENCES

Vitamin D seems to be an effective and safe option to improve QoL and symptoms of IBS. ClinicalTrials.gov (NCT02579902).

Color Vision Deficiency and Functional Disorders Among Israeli Male Adolescents Between 2007 and 2013

Color vision deficiency has been associated with educational difficulties among male children, as well as attention-deficit hyperactivity disorder (ADHD). We examined the association of color vision deficiency with functional conditions, including ADHD, irritable bowel syndrome, enuresis and somatoform disorders, in a large population of male adolescents. We included all Israeli male adolescents that underwent medical and cognitive examinations during conscription between the years 2007 and 2013. The prevalence of ADHD, irritable bowel syndrome, enuresis, and somatoform disorders among color vision deficiency patients was compared to a control group. The study included 305 964 males aging 17 ± 0.6, of which 7584 (2.5%) had color vision deficiency. Using a multivariable analysis, the probability for irritable bowel syndrome, enuresis, and somatoform disorders among color vision deficiency patients was increased by 1.41, 1.94, and 3.87, respectively (P < .05). No significant association was found between ADHD and color vision deficiency. Color vision abnormalities are associated with functional disorders in male adolescents, including irritable bowel syndrome, enuresis, and somatoform disorders.

THE INTESTINAL MICROBIOTA AND THE ROLE OF PROBIOTICS IN IRRITABLE BOWEL SYNDROME: a review

Irritable bowel syndrome is a common, chronic relapsing gastrointestinal disorder that affects 7%-22% of the population worldwide. According to Rome III Criteria, the disorder is defined by the coexistence of abdominal discomfort or pain associated with an alteration in bowel habits. Its pathophysiology is not completely understood but, in addition to some important abnormalities, the disturbed intestinal microbiota has also been described supported by several strands of evidence. The treatment of irritable bowel syndrome is based upon several therapeutic approaches but few have been successful or without adverse events and more recently the gut microbiota and the use of probiotics have emerged as a factor to be considered. Probiotics are live micro-organisms which when consumed in adequate amounts confer a health benefit to the host, such as Lactic bacteria among others. An important scientific rationale has emerged for the use of probiotics in irritable bowel syndrome, although the data regarding different species are still limited. Not all probiotics are beneficial: it is important to select the specific strain which should be supported by good evidence base. The mechanisms of action of probiotics are described and the main strains are quoted.

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease with a high population prevalence. The disorder can be debilitating in some patients, whereas others may have mild or moderate symptoms. The most important single risk factors are female sex, younger age and preceding gastrointestinal infections. Clinical symptoms of IBS include abdominal pain or discomfort, stool irregularities and bloating, as well as other somatic, visceral and psychiatric comorbidities. Currently, the diagnosis of IBS is based on symptoms and the exclusion of other organic diseases, and therapy includes drug treatment of the predominant symptoms, nutrition and psychotherapy. Although the underlying pathogenesis is far from understood, aetiological factors include increased epithelial hyperpermeability, dysbiosis, inflammation, visceral hypersensitivity, epigenetics and genetics, and altered brain-gut interactions. IBS considerably affects quality of life and imposes a profound burden on patients, physicians and the health-care system. The past decade has seen remarkable progress in our understanding of functional bowel disorders such as IBS that will be summarized in this Primer.

Centrally Mediated Disorders of Gastrointestinal Pain

Centrally Mediated Abdominal Pain Syndrome (CAPS), formerly known as Functional Abdominal Pain Syndrome, can be distinguished from other functional GI disorders by its strong central component and relative independence from motility disturbances. CAPS is a result of central sensitization with disinhibition of pain signals rather than increased peripheral afferent excitability. A newly described condition, Narcotic Bowel Syndrome (NBS)/Opioid-Induced GI Hyperalgesia, is characterized by the paradoxical development of or increases in abdominal pain associated with continuous or increasing dosages of opioids. Patients only have relief when opioids are withdrawn. We define both conditions in the context of epidemiology, pathophysiology, clinical evaluation and treatment, emphasizing the importance of a physician-patient relationship in all aspects of care.

Anti-nociceptive effect of Faecalibacterium prausnitzii in non-inflammatory IBS-like models

Visceral pain and intestinal dysbiosis are associated with Irritable Bowel Syndrome (IBS), a common functional gastrointestinal disorder without available efficient therapies. In this study, a decrease of Faecalibacterium prausnitzii presence has been observed in an IBS-like rodent model induced by a neonatal maternal separation (NMS) stress. Moreover, it was investigated whether F. prausnitzii may have an impact on colonic sensitivity. The A2-165 reference strain, but not its supernatant, significantly decreased colonic hypersensitivity induced by either NMS in mice or partial restraint stress in rats. This effect was associated with a reinforcement of intestinal epithelial barrier. Thus, F. prausnitzii exhibits anti-nociceptive properties, indicating its potential to treat abdominal pain in IBS patients.

The origin of segmentation motor activity in the intestine

The segmentation motor activity of the gut that facilitates absorption of nutrients, was first described in the late 19th century but the fundamental mechanisms underlying it remain poorly understood. The dominant theory suggests alternate excitation and inhibition from the enteric nervous system. Here we demonstrate that typical segmentation can occur after total nerve blockade. The segmentation motor pattern emerges when the amplitude of the dominant pacemaker, the slow wave generated by ICC associated with the myenteric plexus (ICC-MP), is modulated by the phase of induced lower frequency rhythmic transient depolarizations, generated by ICC associated with the deep muscular plexus (ICC-DMP), resulting in a waxing and waning of the amplitude of the slow wave and a rhythmic checkered pattern of segmentation motor activity. Phase amplitude modulation of the slow waves points to an underlying system of coupled nonlinear oscillators originating in ICC.

Faecalibacterium prausnitzii prevents physiological damages in a chronic low-grade inflammation murine model

BACKGROUND

The human gut houses one of the most complex and abundant ecosystems composed of up to 10(13)-10(14) microorganisms. The importance of this intestinal microbiota is highlighted when a disruption of the intestinal ecosystem equilibrium appears (a phenomenon called dysbiosis) leading to an illness status, such as inflammatory bowel diseases (IBD). Indeed, the reduction of the commensal bacterium Faecalibacterium prausnitzii (one of the most prevalent intestinal bacterial species in healthy adults) has been correlated with several diseases, including IBD, and most importantly, it has been shown that this bacterium has anti-inflammatory and protective effects in pre-clinical models of colitis. Some dysbiosis disorders are characterized by functional and physiological alterations. Here, we report the beneficial effects of F. prausnitzii in the physiological changes induced by a chronic low-grade inflammation in a murine model. Chronic low-grade inflammation and gut dysfunction were induced in mice by two episodes of dinitro-benzene sulfonic acid (DNBS) instillations. Markers of inflammation, gut permeability, colonic serotonin and cytokine levels were studied. The effects of F. prausnitzii strain A2-165 and its culture supernatant (SN) were then investigated.

RESULTS

No significant differences were observed in classical inflammation markers confirming that inflammation was subclinical. However, gut permeability, colonic serotonin levels and the colonic levels of the cytokines IL-6, INF-γ, IL-4 and IL-22 were higher in DNBS-treated than in untreated mice. Importantly, mice treated with either F. prausnitzii or its SN exhibited significant decreases in intestinal permeability, tissue cytokines and serotonin levels.

CONCLUSIONS

Our results show that F. prausnitzii and its SN had beneficial effects on intestinal epithelial barrier impairment in a chronic low-grade inflammation model. These observations confirm the potential of this bacterium as a novel probiotic treatment in the management of gut dysfunction and low-grade inflammation.

Risk of irritable bowel syndrome in first-degree, second-degree and third-degree relatives of affected individuals: a nationwide family study in Sweden

OBJECTIVES

IBS aggregates in families, but the familial risk of IBS has only been determined in first-degree relatives and spouses. This nationwide study aimed to determine the familial risk of IBS in first-degree, second-degree, and third-degree relatives and spouses of affected individuals in order to estimate the relative influences of genes and shared family environment.

METHODS

We performed a case-cohort study. The Swedish Multigeneration Register was linked to the Hospital Discharge Register for the period 1987-2010 and the Swedish Outpatient Care Register for 2001-2010. ORs for IBS were calculated for relatives of individuals who had been diagnosed with IBS compared with relatives of individuals unaffected by IBS as the reference group. ORs were also determined for IBS cases diagnosed in primary healthcare in four Swedish counties (2001-2007).

RESULTS

The ORs for IBS were 1.75 in siblings (95% CI 1.63 to 1.89), 1.82 in offspring (1.67 to 1.97), 1.90 in parents (1.76 to 2.05), 1.10 in maternal half-siblings (0.88 to 1.39), 1.78 in paternal half-siblings (1.48 to 2.15), 1.27 in nieces/nephews (1.18 to 1.38), 1.11 in cousins (1.04 to 1.18), and 1.51 in spouses (1.24 to 1.84) of probands diagnosed with IBS. The OR for probands diagnosed in primary healthcare was 1.82 in siblings (1.52 to 2.18), and 1.82 in offspring (1.49 to 2.21).

CONCLUSIONS

The increased IBS risk among first-degree relatives and also second-degree and third-degree relatives indicates a genetic component of the familial clustering of IBS. However, a non-genetic contribution is also suggested by the increased risk among spouses.

Test-positive rate at CT colonography is increased by rectal bleeding and/or unexplained weight loss, unlike other common gastrointestinal symptoms

PURPOSE

We evaluated the rate of significant colonic and extra-colonic abnormalities at computed tomography colonography (CTC), according to symptoms and age.

MATERIALS AND METHODS

We retrospectively evaluated 7361 consecutive average-risk subjects (3073 males, average age: 60.3 ± 13.9; range 18-96 years) for colorectal cancer (CRC) who underwent CTC. They were divided into three groups according to clinical symptoms: 1343 asymptomatic individuals (group A), 899 patients with at least one "alarm" symptom for CRC, including rectal bleeding and unexplained weight loss (group C), and 5119 subjects with other gastrointestinal symptoms (group B). Diagnostic and test-positive rates of CTC were established using optical colonoscopy (OC) and/or surgery as reference standard. In addition, clinically significant extra-colonic findings were noted.

RESULTS

903 out of 7361 (12%, 95% confidence interval (CI) 0.11-0.13) subjects had at least one clinically significant colonic finding at CTC. CTC true positive fraction and false positive fraction were respectively 637/642 (99.2%, 95%CI 0.98-0.99) and 55/692 (7.95%, 95%CI 0.05-0.09). The pooled test-positive rate in group C (138/689, 20.0%, 95%CI 0.17-0.23) was significantly higher than in both groups A (79/1343, 5.9%, 95%CI 0.04-0.07) and B (420/5329, 7.5%, 95%CI 0.07-0.08) (p < 0.001). Aging and male gender were associated to a higher test positive rate. The rate of clinically significant extra-colonic findings was significantly higher in group C (44/689, 6.4%, 95%CI 0.04-0.08) versus groups A (26/1343, 1.9%, 95%CI 0.01-0.02) and B (64/5329, 1.2%, 95%CI 0.01-0.02) (p < 0.001).

CONCLUSION

Both test-positive and significant extra-colonic finding rates at CTC are significantly increased in the presence of "alarm" gastrointestinal symptoms especially in older patients.

Corticotrophin-releasing factor 1 activation in the central amygdale and visceral hyperalgesia

Corticotropin-releasing factor (CRF)-CRF1 receptor in the brain plays a key role in stress-related alterations of behavior including anxiety/depression, and autonomic and visceral functions. In particular, CRF1 signaling mediates hypersensitivity to colorectal distension (CRD) in various models (early life adverse events, repeated psychological stress, chronic high anxiety, postcolonic inflammation, or repeated nociceptive CRD). So far, knowledge of brain sites involved is limited. A recent article demonstrates in rats that CRF microinjected into the central amygdala (CeA) induces a hyperalgesic response to CRD and enhances the noradrenaline and dopamine levels at this site. The visceral and noradrenaline, unlike dopamine, responses were blocked by a CRF1 antagonist injected into the CeA. Here, we review the emerging role that CRF-CRF1 signaling plays in the CeA to induce visceral hypersensitivity. In the somatic pain field, CRF in the CeA was shown to induce pain sensitization. This is mediated by the activation of postsynaptic CRF1 receptors and protein kinase A signaling that increases N-methyl-d-aspartate receptor neurotransmission. In addition, the activation of tetraethylamonium-sensitive ion channels such as Kv3 accelerates repolarization and firing rate. Whether facilitation of pain transmission underlies CRF action in the CeA-induced visceral hypersensitivity will need to be delineated. CRF1 signaling in the CeA is also an important component of the neuronal circuitry inducing anxiety-like behavior and positioned at the interphase of the reciprocal relationship between pain and affective state. The hyperactivity of this system may represent the neuroanatomical and biochemical substrate contributing to the coexpression of hypersensitivity to CRD and mood disorders in subsets of irritable bowel syndrome patients.