Post-infectious IBS: Defining its clinical features and prognosis using an internet-based survey

Gender-specific insights into the irritable bowel syndrome pathophysiology. Focus on gut dysbiosis and permeability

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder involving the brain-gut interaction. IBS is characterized by persistent abdominal pain and changes in bowel habits. IBS exerts significant impacts on quality of life and imposes huge economic costs. Global epidemiological data reveal variations in IBS prevalence, both globally and between genders, necessitating comprehensive studies to uncover potential societal and cultural influences. While the exact pathophysiology of IBS remains incompletely understood, the mechanism involves a dysregulation of the brain-gut axis, leading to disturbed intestinal motility, local inflammation, altered intestinal permeability, visceral sensitivity, and gut microbiota composition. We reviewed several gender-related pathophysiological aspects of IBS pathophysiology, by focusing on gut dysbiosis and intestinal permeability. This perspective paves the way to personalized and multidimensional clinical management of individuals with IBS.

Co-Morbidities of Irritable Bowel Syndrome in a Racially and Ethnically Diverse Population

Introduction: Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction (DGBI), and associated co-morbidities worsen quality of life. Research concerning IBS co-morbidities in different racial/ethnic groups is very sparse. This study aimed to determine the prevalence rates of co-morbidities and possible differences in a multiracial/ethnic IBS cohort. Methods: Based on ICD-9-coded IBS diagnosis, 740 outpatients (≥18 years) were included in this retrospective study at Boston Medical Center. Demographics and ICD-9-coded co-morbidities were extracted from electronic records. Descriptive statistics and multiple logistic regression were used for data analyses. Results: The most prevalent co-morbidities in this IBS cohort included gastroesophageal reflux disorder (GERD) (30%), depression (27%), anxiety (23%), (chronic obstructive pulmonary disease) COPD/asthma (16%), and obesity (10%). GERD was more prevalent in Hispanics and Blacks (p = 0.0005), and non-ulcer dyspepsia (NUD) was more prevalent in Blacks and Asians (p = 0.003). Higher rates of diabetes mellitus type 2 (DMT2) (p = 0.0003) and depression (p = 0.03), but not anxiety (p = 0.9), were present in Blacks and Hispanics. GERD was significantly associated with Hispanics (p = 0.003), dependent on age, overweight, and obesity. NUD was significantly associated with Blacks (p = 0.01) and Asians (p = 0.006), independent of sex, age, and BMI. Cancer of the thyroid, ovaries, and testis occurred at a five-fold higher rate than expected. Conclusions: Significant racial/ethnic differences exist for IBS co-morbidities in this study cohort, including depression, DMT2, GERD, and NUD. Certain cancers were found to be more frequent in this IBS sample as compared with the general population.

Risk Factors of Developing Postinfectious Irritable Bowel Syndrome in Shigellosis Patients, 5 Years After Hospitalization During the Outbreak

Background

Irritable bowel syndrome (IBS) can be triggered by bacterial dysentery. This study aimed to investigate postinfectious IBS and its risk factors after the shigellosis outbreak in hospitalized patients.

Methods

This retrospective study was conducted in 2020-2021 in referral hospitals for Shigella gastroenteritis during the 2014 shigellosis outbreak in Isfahan. The Shigella-infected group included hospitalized shigellosis patients with clinical symptoms and positive stool culture. The control group included patients matched pairwise on age and sex to the Shigella-infected group, admitted to the same hospitals in the same period with diagnoses other than shigellosis. Both groups had no history of diagnosed IBS before the outbreak. The incidence of IBS (according to Rome-III criteria) and its related factors was compared between the 2 groups 5 years after infection.

Results

Of 619 participants, 220 (35.5%) were in the Shigella-infected group. The 5-year incidence of IBS was 31.8% and 5.7% in the Shigella-infected and control groups, respectively. Multivariate analysis showed that shigellosis was significantly associated with increased risk of IBS (odds ratio [OR], 17.18 [95% confidence interval {CI}, 9.37-31.48]). Multivariate analysis indicated education level (OR, 4.15 [95% CI, 1.47-11.73]), diarrhea lasting >4 days (OR, 1.69 [95% CI, 1.17-2.44]), and abdominal cramps during the infection (OR, 0.27 [95% CI, .77-.95]) associated with postinfectious IBS (P < .05).

Conclusions

Hospitalized patients with Shigella gastroenteritis are at increased risk of IBS within 5 years after infection. Factors such as higher education level and the absence of abdominal cramps and diarrhea persisting for >5 days during hospitalization can further increase this risk.

Systematic Review and Meta-analysis: Efficacy of Mesalamine in Irritable Bowel Syndrome

BACKGROUND & AIMS

Some patients with irritable bowel syndrome (IBS) demonstrate low-grade inflammation in the intestine. Mesalamine, which has anti-inflammatory effects, may be an efficacious treatment for IBS, but studies are conflicting. We conducted a systematic review and meta-analysis to assess efficacy and safety of mesalamine in IBS.

METHODS

We searched the medical literature up to September 14, 2022, to identify randomized controlled trials (RCTs) of mesalamine in IBS. We judged efficacy and safety using dichotomous assessments of effect on global IBS symptoms, abdominal pain, bowel habit or stool frequency, and occurrence of any adverse event. We pooled data using a random effects model, with efficacy and safety reported as pooled relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

We identified 8 eligible RCTs (820 patients). Mesalamine was more efficacious than placebo for global IBS symptoms (RR of global symptoms not improving, 0.86; 95% CI, 0.79-0.95; number needed to treat = 10; 95% CI, 6-27), but not for abdominal pain or bowel habit or stool frequency. Subgroup analyses demonstrated efficacy of mesalamine in IBS with diarrhea for global IBS symptoms (RR, 0.88; 95% CI, 0.79-0.99), but not patients with other predominant bowel habits or those with post-infection IBS. Adverse event rates were no higher with mesalamine (RR, 1.20; 95% CI, 0.89-1.63) but were reported in only 5 trials.

CONCLUSIONS

Mesalamine may be modestly efficacious for global symptoms in IBS, particularly IBS with diarrhea, but quality of evidence was low. Adequately powered high quality RCTs of mesalamine in IBS are needed.

Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis

BACKGROUND & AIMS

Some probiotics may be beneficial in irritable bowel syndrome (IBS), but differences in species and strains used, as well as endpoints reported, have hampered attempts to make specific recommendations as to which should be preferred. We updated our previous meta-analysis examining this issue.

METHODS

MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to March 2023). Randomized controlled trials (RCTs) recruiting adults with IBS, comparing probiotics with placebo were eligible. Dichotomous symptom data were pooled to obtain a relative risk of global symptoms, abdominal pain, or abdominal bloating or distension persisting after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardized mean difference with a 95% CI. Adverse events data were also pooled.

RESULTS

We identified 82 eligible trials, containing 10,332 patients. Only 24 RCTs were at low risk of bias across all domains. For global symptoms, there was moderate certainty in the evidence for a benefit of Escherichia strains, low certainty for Lactobacillus strains and Lactobacillus plantarum 299V, and very low certainty for combination probiotics, LacClean Gold S, Duolac 7s, and Bacillus strains. For abdominal pain, there was low certainty in the evidence for a benefit of Saccharomyces cerevisae I-3856 and Bifidobacterium strains, and very low certainty for combination probiotics, Lactobacillus, Saccharomyces, and Bacillus strains. For abdominal bloating or distension there was very low certainty in the evidence for a benefit of combination probiotics and Bacillus strains. The relative risk of experiencing any adverse event, in 55 trials, including more than 7000 patients, was not significantly higher with probiotics.

CONCLUSIONS

Some combinations of probiotics or strains may be beneficial in IBS. However, certainty in the evidence for efficacy by GRADE criteria was low to very low across almost all of our analyses.

Genetic Variants in Carbohydrate Digestive Enzyme and Transport Genes Associated with Risk of Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is characterized by abdominal pain and alterations in bowel pattern, such as constipation (IBS-C), diarrhea (IBS-D), or mixed (IBS-M). Since malabsorption of ingested carbohydrates (CHO) can cause abdominal symptoms that closely mimic those of IBS, identifying genetic mutations in CHO digestive enzymes associated with IBS symptoms is critical to ascertain IBS pathophysiology. Through candidate gene association studies, we identify several common variants in TREH, SI, SLC5A1 and SLC2A5 that are associated with IBS symptoms. By investigating rare recessive Mendelian or oligogenic inheritance patterns, we identify case-exclusive rare deleterious variation in known disease genes (SI, LCT, ALDOB, and SLC5A1) as well as candidate disease genes (MGAM and SLC5A2), providing potential evidence of monogenic or oligogenic inheritance in a subset of IBS cases. Finally, our data highlight that moderate to severe IBS-associated gastrointestinal symptoms are often observed in IBS cases carrying one or more of deleterious rare variants.

Sadness and Anxiety Modify the Relationship Between COVID-19 and Gastrointestinal Symptoms at 6-12 Months of Follow-up

Background and Aims

It is unclear to what degree post-COVID-19 gastrointestinal (GI) symptoms are caused by the SARS-CoV-2 virus vs psychological factors related to the stress of the pandemic. To evaluate this, we compared rates of long-term GI and mental health symptoms in patients testing positive vs negative for SARS-CoV-2.

Methods

Adults presenting for SARS-CoV-2 testing from April to November 2020 were prospectively enrolled in a longitudinal cohort. Six to 12 months later, the presence and severity of current GI and mental health symptoms were assessed on a 5-point Likert scale. A multivariable logistic regression model was used to estimate the odds of a positive COVID test for predicting GI symptoms, stratified by sadness/anxiety.

Results

749 COVID-positive and 107 COVID-negative patients completed the survey. The prevalence of at least one GI symptom was higher in patients with COVID-19 (29 vs 18%, P = .01). However, after stratifying by sadness/anxiety, differences in GI symptoms according to COVID status were no longer significant. On multivariable analysis, the adjusted odds ratio for GI symptoms was 8.26 (95% CI 4.04-16.9) for positive COVID with sadness/anxiety, 8.74 (95% CI 2.63-29.0) for negative COVID with sadness/anxiety, and 1.16 (95% CI 0.57-2.39) for positive COVID without sadness/anxiety, compared to a reference group of negative COVID without sadness/anxiety.

Conclusion

After accounting for sadness and anxiety, there was no association between COVID-19 and the development of long-term GI symptoms. Post-COVID GI symptoms may be mediated bidirectionally through coexisting anxiety and depression, similar to disorders of gut-brain interaction.

Fibromyalgia and Irritable Bowel Syndrome Interaction: A Possible Role for Gut Microbiota and Gut-Brain Axis

Fibromyalgia (FM) is a serious chronic pain syndrome, characterised by muscle and joint stiffness, insomnia, fatigue, mood disorders, cognitive dysfunction, anxiety, depression and intestinal irritability. Irritable Bowel Syndrome (IBS) shares many of these symptoms, and FM and IBS frequently co-exist, which suggests a common aetiology for the two diseases. The exact physiopathological mechanisms underlying both FM and IBS onset are unknown. Researchers have investigated many possible causes, including alterations in gut microbiota, which contain billions of microorganisms in the human digestive tract. The gut-brain axis has been proven to be the link between the gut microbiota and the central nervous system, which can then control the gut microbiota composition. In this review, we will discuss the similarities between FM and IBS. Particularly, we will focus our attention on symptomatology overlap between FM and IBS as well as the similarities in microbiota composition between FM and IBS patients. We will also briefly discuss the potential therapeutic approaches based on microbiota manipulations that are successfully used in IBS and could be employed also in FM patients to relieve pain, ameliorate the rehabilitation outcome, psychological distress and intestinal symptoms.

Postinfective bowel dysfunction following Campylobacter enteritis is characterised by reduced microbiota diversity and impaired microbiota recovery

OBJECTIVES

Persistent bowel dysfunction following gastroenteritis (postinfectious (PI)-BD) is well recognised, but the associated changes in microbiota remain unclear. Our aim was to define these changes after gastroenteritis caused by a single organism, Campylobacter jejuni, examining the dynamic changes in the microbiota and the impact of antibiotics.

DESIGN

A single-centre cohort study of 155 patients infected with Campylobacter jejuni. Features of the initial illness as well as current bowel symptoms and the intestinal microbiota composition were recorded soon after infection (visit 1, <40 days) as well as 40-60 days and >80 days later (visits 2 and 3). Microbiota were assessed using 16S rRNA sequencing.

RESULTS

PI-BD was found in 22 of the 99 patients who completed the trial. The cases reported significantly looser stools, with more somatic and gastrointestinal symptoms. Microbiota were assessed in 22 cases who had significantly lower diversity and altered microbiota composition compared with the 44 age-matched and sex-matched controls. Moreover 60 days after infection, cases showed a significantly lower abundance of 23 taxa including phylum Firmicutes, particularly in the order Clostridiales and the family Ruminoccocaceae, increased Proteobacteria abundance and increased levels of Fusobacteria and Gammaproteobacteria. The microbiota changes were linked with diet; higher fibre consumption being associated with lower levels of Gammaproteobacteria.

CONCLUSION

The microbiota of PI-BD patients appeared more disturbed by the initial infection compared with the microbiota of those who recovered. The prebiotic effect of high fibre diets may inhibit some of the disturbances seen in PI-BD.

TRIAL REGISTRATION NUMBER

NCT02040922.

Incidence and predisposing factors for de novo post-COVID-19 irritable bowel syndrome

OBJECTIVE

Postinfectious irritable bowel syndrome (IBS) is a known entity. We evaluated the incidence of post-COVID-19 IBS in patients discharged from the hospital and analyzed its correlation with the clinical and laboratory parameters, and treatment during the hospital stay.

METHODS

Three hundred three COVID-19 hospitalized patients without prior history of IBS were prospectively followed after their discharge and were evaluated as per Rome-IV criteria for IBS.

RESULTS

One hundred seventy-eight patients were males (58.7%). The age range was 17-95 years (mean ± SD, 55.9 ± 15.8). A total of 194 (64%) had mild COVID-19, 74 (24.4%) had moderate COVID-19, whereas 35 (11.6%) had severe COVID-19 infection. Sixteen (5.3%) patients had concomitant GI symptoms during COVID-19 infection. IBS symptoms were found to be present in 32 (10.6%) patients, out of which 17 (53.13%) had diarrhea-predominant, 10 (31.25%) had constipation-predominant, and five (15.62%) had mixed-type IBS. Post-COVID-19 IBS was more common in the female sex (P < 0.001), concomitant GI symptoms with COVID-19 (P < 0.001), oxygen requirement (P = 0.015), deranged liver function tests at the time of admission (P = 0.002), high procalcitonin (P = 0.013), high C-reactive protein levels (P = 0.035); whereas negative correlation was found with remdesivir treatment (P = 0.047). After performing regression analysis, female sex (P < 0.001), oxygen requirement during hospital stay (P = 0.016), GI symptoms during COVID-19 infection (P < 0.001), and high procalcitonin levels (P = 0.017) were independently associated with post-COVID-19 IBS.

CONCLUSION

GI symptoms during active COVID-19 infection increase the chances of developing post-COVID-19 IBS. The risk of developing post-COVID-19 IBS increases in female patients, those requiring oxygen and having high procalcitonin levels during COVID-19 infection.

Progress in research of low-grade inflammation in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common intestinal disease with a prevalence of 10%-15%. However, its pathophysiology is still not completely clear, and it has long been considered as a functional disease. In recent years, it has been found that low-grade inflammation plays a pathogenic role in IBS. Studies have confirmed that there is persistent mucosal inflammation at the microscopic and molecular levels. This review discusses the evidence, role, and clinical relevance of mucosal inflammation in IBS. In addition to mucosal inflammation, neuroinflammation may lead to changes in neuroendocrine pathways and glucocorticoid receptor genes through the "gut-brain" axis, and thus cause IBS through proinflammatory phenotype and hypothalamic pituitary adrenal axis and 5-hydroxytryptamine dysfunction. The observation that IBS patients can benefit from anti-inflammatory therapy also confirms that IBS is associated with inflammation.

Decreased Gut Microbiome Tryptophan Metabolism and Serotonergic Signaling in Patients With Persistent Mental Health and Gastrointestinal Symptoms After COVID-19

INTRODUCTION

An estimated 15%-29% of patients report new gastrointestinal (GI) symptoms after coronavirus-19 disease (COVID-19) while 4%-31% report new depressive symptoms. These symptoms may be secondary to gut microbiome tryptophan metabolism and 5-hydroxytryptamine (5-HT)-based signaling.

METHODS

This study used specimens from 2 patient cohorts: (i) fecal samples from patients with acute COVID-19 who participated in a randomized controlled trial testing prebiotic fiber and (ii) blood samples from patients with acute COVID-19. Six months after recovering from COVID-19, both cohorts answered questions related to GI symptoms and anxiety or depression. Microbiome composition and function, focusing on tryptophan metabolism-associated pathways, and plasma 5-HT were assessed.

RESULTS

In the first cohort (n = 13), gut microbiome L-tryptophan biosynthesis during acute COVID-19 was decreased among those who developed more severe GI symptoms (2.0-fold lower log activity comparing those with the most severe GI symptoms vs those with no symptoms, P = 0.06). All tryptophan pathways showed decreased activity among those with more GI symptoms. The same pathways were also decreased in those with the most severe mental health symptoms after COVID-19. In an untargeted analysis, 5 additional metabolic pathways significantly differed based on subsequent development of GI symptoms. In the second cohort (n = 39), plasma 5-HT concentration at the time of COVID-19 was increased 5.1-fold in those with GI symptoms alone compared with those with mental health symptoms alone ( P = 0.02).

DISCUSSION

Acute gut microbiome-mediated reduction in 5-HT signaling may contribute to long-term GI and mental health symptoms after COVID-19. Future studies should explore modification of 5-HT signaling to reduce post-COVID symptoms.

5-HT7 receptor-dependent intestinal neurite outgrowth contributes to visceral hypersensitivity in irritable bowel syndrome

Irritable bowel syndrome (IBS) is characterized by visceral hypersensitivity (VH) associated with abnormal serotonin/5-hydroxytryptamine (5-HT) metabolism and neurotrophin-dependent mucosal neurite outgrowth. The underlying mechanisms of VH remain poorly understood. We investigated the role of 5-HT₇ receptor in mucosal innervation and intestinal hyperalgesia. A high density of mucosal nerve fibres stained for 5-HT₇ was observed in colonoscopic biopsy specimens from IBS patients compared with those from healthy controls. Staining of 5-HT₃ and 5-HT₄ receptors was observed mainly in colonic epithelia with comparable levels between IBS and controls. Visceromotor responses to colorectal distension were evaluated in two mouse models, one postinfectious with Giardia and subjected to water avoidance stress (GW) and the other postinflammatory with trinitrobenzene sulfonic acid-induced colitis (PT). Increased VH was associated with higher mucosal density of 5-HT₇-expressing nerve fibres and elevated neurotrophin and neurotrophin receptor levels in the GW and PT mice. The increased VH was inhibited by intraperitoneal injection of SB-269970 (a selective 5-HT₇ antagonist). Peroral multiple doses of CYY1005 (a novel 5-HT₇ ligand) decreased VH and reduced mucosal density of 5-HT₇-expressing nerve fibres in mouse colon. Human neuroblastoma SH-SY5Y cells incubated with bacteria-free mouse colonic supernatant, 5-HT, nerve growth factor, or brain-derived neurotrophic factor exhibited nerve fibre elongation, which was inhibited by 5-HT₇ antagonists. Gene silencing of HTR7 also reduced the nerve fibre length. Activation of 5-HT₇ upregulated NGF and BDNF gene expression, while stimulation with neurotrophins increased the levels of tryptophan hydroxylase 2 and 5-HT₇ in neurons. A positive-feedback loop was observed between serotonin and neurotrophin pathways via 5-HT₇ activation to aggravate fibre elongation, whereby 5-HT₃ and 5-HT₄ had no roles. In conclusion, 5-HT₇-dependent mucosal neurite outgrowth contributed to VH. A novel 5-HT₇ antagonist could be used as peroral analgesics for IBS-related pain.

Factors related to irritable bowel syndrome and differences among subtypes: A cross-sectional study in the UK Biobank

Background: Irritable bowel syndrome (IBS) reduces patients' quality of life and causes great burdens due to its unclear pathogenesis and criteria for diagnosis. This study aimed to explore the differences in prevalence and the influencing factors for IBS and its subtypes. Methods: The UK Biobank surveyed 174,771 adult participants who completed the Digestive Health Questionnaire (DHQ) through emails and websites. DHQ included the Rome III criteria, IBS symptom severity score, and Patient Health Questionnaire 12 Somatic Symptom score. The UK Biobank also asked regarding previous IBS diagnosis, diagnosis for post-infectious IBS (PI-IBS), and environmental exposures and associated conditions (including anxiety or depression, based on treatment sought or offered). Pearson's Chi-squared test or Wilcoxon's rank-sum test was used for potential associations. Binary logic regression based on sex stratification was used to examine associations between selected factors and IBS and its subtypes. Results: This study included 31,918 participants who met the Rome III criteria for IBS. The pooled prevalence of IBS in the UK Biobank was 18.3%, with mixed IBS as the predominant subtype (59.0%), followed by diarrhea-predominant IBS (25.1%), constipation-predominant IBS (14.7%), and untyped IBS (1.1%). IBS was significantly associated with somatization (male: OR = 5.326, 95% CI = 4.863-5.832; female: OR = 4.738, 95% CI = 4.498-4.992) and coeliac disease (male: OR = 4.107, 95% CI = 3.132-5.385; female: OR = 3.783, 95% CI = 3.310-4.323). Differences in antibiotics and mental status were presented among subtypes and sex. Furthermore, 1,787 individuals were diagnosed with PI-IBS in the group of patients with IBS. The prevalence of PI-IBS in IBS was 16.6% in the UK Biobank, and it was characterized by diarrhea, fever, bloody diarrhea, and vomiting. Conclusion: Somatization and coeliac disease are primary risk factors for IBS. Distinguishing differential risk factors is critical for the precise diagnosis and treatment of IBS subtypes, particularly sex-specific differences in mental health status. General practitioners should focus on the treatment according to IBS subtypes.

Extraintestinal manifestations in irritable bowel syndrome: A systematic review

BACKGROUND

Irritable bowel syndrome (IBS) is characterized by abdominal pain and altered bowel habits. Further, IBS patients experience a high degree of extraintestinal symptoms.

OBJECTIVES

The aim of this review was to describe the relation between IBS and extraintestinal manifestations and mechanisms and treatments of these extraintestinal manifestations.

DESIGN

The study was performed as a systematic review.

DATA SOURCES AND METHODS

Search terms including extraintestinal manifestations or somatization and IBS were used to scrutinize for publications in Pubmed. In total, 630 publications were identified and 80 were finally included in this review.

RESULTS

About 50% of all IBS patients have extraintestinal manifestations in addition to gastrointestinal symptoms. Somatic pain, fatigue, and sleeping disturbances are most common, and most often described in women. Both extraintestinal manifestations and psychological distress are associated with exaggerated gastrointestinal symptoms, impaired quality of life, and difficulties to treat IBS symptoms. The extraintestinal manifestations render an excess of healthcare costs. Varying etiology and pathophysiology to IBS are discussed, and many patients express a general hypersensitivity. Extraintestinal symptoms are seldom documented at clinical healthcare or included in the assessment of treatment outcomes. A good patient-physician relationship and strengthening of coping mechanisms have rendered less gastrointestinal symptoms, psychological distress, and somatization. Altered lifestyle habits may improve both gastrointestinal and extraintestinal symptoms. Pharmacological treatment, including antidepressant drugs, should be considered when lifestyle advice fails. Teamwork between different specialists and healthcare providers may be of importance in the wide range of symptoms and extraintestinal manifestations.

CONCLUSION

Extraintestinal manifestations are common in IBS patients and is associated with worse suffering and difficulties to treat symptoms. Evaluation and treatment of IBS patients should consider also extraintestinal manifestations and their treatment outcome. Establishment of good relationship, strengthening of coping mechanisms, and education in healthier lifestyle habits are crucial in the management of these patients.

Gut microbiota signatures and modulation in irritable bowel syndrome

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

Prevalence and risk factors for gastrointestinal symptoms after recovery from COVID-19

BACKGROUND

COVID-19 frequently presents with acute gastrointestinal (GI) symptoms, but it is unclear how common these symptoms are after recovery. The purpose of this study was to estimate the prevalence and characteristics of GI symptoms after COVID-19.

METHODS

The medical records of patients hospitalized with COVID-19 between March 1 and June 30, 2020, were reviewed for the presence of GI symptoms at primary care follow-up 1 to 6 months later. The prevalence of new GI symptoms was estimated, and risk factors were assessed. Additionally, an anonymous survey was used to determine the prevalence of new GI symptoms among online support groups for COVID-19 survivors.

KEY RESULTS

Among 147 patients without pre-existing GI conditions, the most common GI symptoms at the time of hospitalization for COVID-19 were diarrhea (23%), nausea/vomiting (21%), and abdominal pain (6.1%), and at a median follow-up time of 106 days, the most common GI symptoms were abdominal pain (7.5%), constipation (6.8%), diarrhea (4.1%), and vomiting (4.1%), with 16% reporting at least one GI symptom at follow-up (95% confidence interval 11 to 23%). Among 285 respondents to an online survey for self-identified COVID-19 survivors without pre-existing GI symptoms, 113 (40%) reported new GI symptoms after COVID-19 (95% CI 33.9 to 45.6%).

CONCLUSION AND INFERENCES

At a median of 106 days after discharge following hospitalization for COVID-19, 16% of unselected patients reported new GI symptoms at follow-up. 40% of patients from COVID survivor groups reported new GI symptoms. The ongoing GI effects of COVID-19 after recovery require further study.

Postinfectious onset in functional dyspepsia is a risk factor for weight loss

BACKGROUND

Functional dyspepsia (FD) is differentiated into two subgroups: the postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). Acute gastroenteritis and Helicobacter pylori (HP) infection have been identified as risk factors for FD. It is unclear how these risk factors relate to Rome IV subgroups and their clinical impact. We aimed to study the association of postinfectious FD (PI-FD) and HP status with clinical profiles and weight loss.

METHODS

Consecutive FD patients were assessed for symptom frequency and severity. Patients were identified as PDS, EPS or the overlap group according to severity scores. Additionally, PI history and HP status were determined.

RESULTS

In a cohort of 459 FD-patients, 36% were characterized as having PDS, 9% as having EPS and 55% showed overlap. PI onset and positive HP status were reported by, respectively, 20% and 14% of patients, not significantly differing between subgroups (respectively, p = 0.31 and p = 0.40). Weight loss was reported by 63% in PDS, 36% in EPS and 56% in overlap patients (p = 0.011). Only early satiety severity correlated with more severe weight loss in the PDS (r 0.31, p < 0.0001) and overlap group (r 0.38, p < 0.0001). PI-FD patients were more likely to experience weight loss (OR 2.27, p = 0.0013). HP status was not significantly associated with weight loss (p = 0.90).

CONCLUSION

In this cohort, PI onset of FD symptoms emerged as a risk factor for weight loss, but was not associated with the symptom patterns of PDS, EPS or overlap subgroups. Patients with HP infection were not more likely to experience important weight loss.

AhR/IL-22 pathway as new target for the treatment of post-infectious irritable bowel syndrome symptoms

Alterations in brain/gut/microbiota axis are linked to Irritable Bowel Syndrome (IBS) physiopathology. Upon gastrointestinal infection, chronic abdominal pain and anxio-depressive comorbidities may persist despite pathogen clearance leading to Post-Infectious IBS (PI-IBS). This study assesses the influence of tryptophan metabolism, and particularly the microbiota-induced AhR expression, on intestinal homeostasis disturbance following gastroenteritis resolution, and evaluates the efficacy of IL-22 cytokine vectorization on PI-IBS symptoms. The Citrobacter rodentium infection model in C57BL6/J mice was used to mimic Enterobacteria gastroenteritis. Intestinal homeostasis was evaluated as low-grade inflammation, permeability, mucosa-associated microbiota composition, and colonic sensitivity. Cognitive performances and emotional state of animals were assessed using several tests. Tryptophan metabolism was analyzed by targeted metabolomics. AhR activity was evaluated using a luciferase reporter assay method. One Lactococcus lactis strain carrying an eukaryotic expression plasmid for murine IL-22 (L. lactisIL-22) was used to induce IL-22 production in mouse colonic mucosa. C. rodentium-infected mice exhibited persistent colonic hypersensitivity and cognitive impairments and anxiety-like behaviors after pathogen clearance. These post-infectious disorders were associated with low-grade inflammation, increased intestinal permeability, decrease of Lactobacillaceae abundance associated with the colonic layer, and increase of short-chain fatty acids (SCFAs). During post-infection period, the indole pathway and AhR activity were decreased due to a reduction of tryptophol production. Treatment with L. lactisIL-22 restored gut permeability and normalized colonic sensitivity, restored cognitive performances and decreased anxiety-like behaviors. Data from the video-tracking system suggested an upgrade of welfare for mice receiving the L.lactisIL-22 strain. Our findings revealed that AhR/IL-22 signaling pathway is altered in a preclinical PI-IBS model. IL-22 delivering alleviate PI-IBS symptoms as colonic hypersensitivity, cognitive impairments, and anxiety-like behaviors by acting on intestinal mucosa integrity. Thus, therapeutic strategies targeting this pathway could be developed to treat IBS patients suffering from chronic abdominal pain and associated well-being disorders.

Review article: epidemiology of IBS and other bowel disorders of gut-brain interaction (DGBI)

The disorders of gut-brain interactions (DGBI) are a spectrum of gastrointestinal (GI) disorders that involve the entire GI tract and are usually categorised into four major anatomic GI regions, oesophageal, gastroduodenal, bowel and anorectal. Irritable bowel syndrome (IBS), a bowel DGBI, is one of the most researched DGBI and has been the subject of copious epidemiological studies. Prevalence rates are based on diagnostic criteria. In the case of IBS, there are three central obstacles to attaining a clear picture of prevalence: the absence of biomarkers, the multitude of diagnostic criteria used over the years, and the heterogeneous nature of the methodology used in epidemiologic surveys. When the results of multiple studies, conducted over a long period of time, using different diagnostic criteria and different research methodology, and involving different study populations are pooled to determine a single summary prevalence rate it is difficult to interpret the results and to determine their reliability and significance. This pitfall is insufficiently recognised and unfortunate because prevalence rates are important for understanding the burden of disease, for allocating healthcare and research resources, and for incentivising and prioritising new treatments. The aims of the present paper are to highlight our knowledge and understanding of IBS epidemiology within the context of other DGBI, and to present strategies to improve epidemiological research, especially in advance of the new Rome V criteria, to be published in 2026.

Targeting the Gut Microbiota to Relieve the Symptoms of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common, chronic, functional disorder with a large impact on world population. Its pathophysiology is not completely revealed; however, it is certain that dysregulation of the bidirectional communications between the central nervous system (CNS) and the gut leads to motility disturbances, visceral hypersensitivity, and altered CNS processing characterized by differences in brain structure, connectivity and functional responsiveness. Emerging evidence suggests that gut microbiota exerts a marked influence on the host during health and disease. Gut microbiome disturbances can be also important for development of IBS symptoms and its modulation efficiently contributes to the therapy. In this work, we review the current knowledge about the IBS therapy, the role of gut microbiota in pathogenesis of IBS, and we discuss that its targeting may have significant impact on the effectiveness of IBS therapy.

Epidemiology and Burden of Irritable Bowel Syndrome: An International Perspective

Irritable bowel syndrome (IBS) prevalence rates are based on diagnostic criteria, the basis for case definitions. Diagnostic criteria have a substantial impact on prevalence rates, which are significant for understanding burden of disease, comparing global subpopulations, generating pathophysiologic research, allocating of health care and research resources, and incentivizing and prioritizing new treatments. There are substantial methodological pitfalls in epidemiologic research, so determining regional and global IBS prevalence rates is problematic. The Rome Foundation Global Epidemiology Study was designed to resolve these problems and achieve more valid results. The results of this study are presented in detail; future directions are discussed.

British Society of Gastroenterology guidelines on the management of irritable bowel syndrome

Irritable bowel syndrome (IBS) remains one of the most common gastrointestinal disorders seen by clinicians in both primary and secondary care. Since publication of the last British Society of Gastroenterology (BSG) guideline in 2007, substantial advances have been made in understanding its complex pathophysiology, resulting in its re-classification as a disorder of gut-brain interaction, rather than a functional gastrointestinal disorder. Moreover, there has been a considerable amount of new evidence published concerning the diagnosis, investigation and management of IBS. The primary aim of this guideline, commissioned by the BSG, is to review and summarise the current evidence to inform and guide clinical practice, by providing a practical framework for evidence-based management of patients. One of the strengths of this guideline is that the recommendations for treatment are based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of trial-based and network meta-analyses assessing the efficacy of dietary, pharmacological and psychological therapies in treating IBS. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system, summarising both the strength of the recommendations and the overall quality of evidence. Finally, this guideline identifies novel treatments that are in development, as well as highlighting areas of unmet need for future research.

Mechanism of mast cell-mediated COX2-PGE2-Eps signaling pathway in visceral hypersensitivity in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder (FGID) whose pathophysiological mechanism is complex, involving genetic factors, psychosocial factors, low-grade mucosal inflammation, changes in the intestinal barrier, bacterial flora disorder, neuroimmune abnormalities, and high visceral sensitivity. In recent years, the mechanism of visceral hypersensitivity in IBS has become a hot research topic. Mast cells (MCs) are a group of immune cells that are distributed in the central nervous system and digestive system. The COX2-PGE2-Eps signaling pathway plays a major role in the visceral hypersensitivity in IBS, from peripheral sensitization to central sensitization, which provides a new idea for further clarifying the pathological mechanism of IBS.

Local immune response to food antigens drives meal-induced abdominal pain

Up to 20% of people worldwide develop gastrointestinal symptoms following a meal¹, leading to decreased quality of life, substantial morbidity and high medical costs. Although the interest of both the scientific and lay communities in this issue has increased markedly in recent years, with the worldwide introduction of gluten-free and other diets, the underlying mechanisms of food-induced abdominal complaints remain largely unknown. Here we show that a bacterial infection and bacterial toxins can trigger an immune response that leads to the production of dietary-antigen-specific IgE antibodies in mice, which are limited to the intestine. Following subsequent oral ingestion of the respective dietary antigen, an IgE- and mast-cell-dependent mechanism induced increased visceral pain. This aberrant pain signalling resulted from histamine receptor H₁-mediated sensitization of visceral afferents. Moreover, injection of food antigens (gluten, wheat, soy and milk) into the rectosigmoid mucosa of patients with irritable bowel syndrome induced local oedema and mast cell activation. Our results identify and characterize a peripheral mechanism that underlies food-induced abdominal pain, thereby creating new possibilities for the treatment of irritable bowel syndrome and related abdominal pain disorders.

Deprivation of dietary fiber in specific-pathogen-free mice promotes susceptibility to the intestinal mucosal pathogen Citrobacter rodentium

The change of dietary habits in Western societies, including reduced consumption of fiber, is linked to alterations in gut microbial ecology. Nevertheless, mechanistic connections between diet-induced microbiota changes that affect colonization resistance and enteric pathogen susceptibility are still emerging. We sought to investigate how a diet devoid of soluble plant fibers impacts the structure and function of a conventional gut microbiota in specific-pathogen-free (SPF) mice and how such changes alter susceptibility to a rodent enteric pathogen. We show that absence of dietary fiber intake leads to shifts in the abundances of specific taxa, microbiome-mediated erosion of the colonic mucus barrier, a reduction of intestinal barrier-promoting short-chain fatty acids, and increases in markers of mucosal barrier integrity disruption. Importantly, our results highlight that these low-fiber diet-induced changes in the gut microbial ecology collectively contribute to a lethal colitis by the mucosal pathogen Citrobacter rodentium, which is used as a mouse model for enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Our study indicates that modern, low-fiber Western-style diets might make individuals more prone to infection by enteric pathogens via the disruption of mucosal barrier integrity by diet-driven changes in the gut microbiota, illustrating possible implications for EPEC and EHEC infections.

Functional gastrointestinal disorders: advances in understanding and management

Gastrointestinal symptoms are highly prevalent, but many people who have them will have no organic explanation for their symptoms. Most of these people will be labelled as having a functional gastrointestinal disorder, such as irritable bowel syndrome, functional dyspepsia, or functional constipation. These conditions affect up to 40% of people at any one point in time, and two-thirds of these people will have chronic, fluctuating symptoms. The pathophysiology of functional gastrointestinal disorders is complex, but involves bidirectional dysregulation of gut-brain interaction (via the gut-brain axis), as well as microbial dysbiosis within the gut, altered mucosal immune function, visceral hypersensitivity, and abnormal gastrointestinal motility. Hence, nomenclature refers to the conditions as disorders of gut-brain interaction. Psychological comorbidity is common; however, whether or not this predates, or is driven by, symptoms is not clear. Patients with functional gastrointestinal disorders can feel stigmatised, and often this diagnosis is not communicated effectively by physicians, nor is education provided. Prompt identification and treatment of these conditions is crucial as they have a considerable impact on health-care systems and society as a whole because of repeated consultations, unnecessary investigations and surgeries, prescriptions and over-the-counter medicine use, and impaired health-related quality of life and ability to work. Symptom-based criteria are used to make a diagnosis, with judicious use of limited investigations in some patients. The general principles of treatment are based on a biopsychosocial understanding and involve management of physical symptoms and, if present, psychological comorbidity. In the future, treatment approaches to functional gastrointestinal disorders are likely to become more personalised, based not only on symptoms but also underlying pathophysiology and psychology.

Irritable bowel syndrome

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

Global burden of irritable bowel syndrome: trends, predictions and risk factors

Irritable bowel syndrome (IBS) is one of the most common disorders of gut-brain interaction worldwide, defined according to patterns of gastrointestinal symptoms as described by the Rome diagnostic criteria. However, these criteria, developed with reference to research conducted largely in Western populations, might be limited in their applicability to other countries and cultures. Epidemiological data show a wide variation in the prevalence of IBS globally and more rigorous studies are needed to accurately determine any differences that might exist between countries as well as the potential explanations. The effects of IBS on the individual, in terms of their quality of life, and on health-care delivery and society, in terms of economic costs, are considerable. Although the magnitude of these effects seems to be comparable between nations, their precise nature can vary based on the existence of societal and cultural differences. The pathophysiology of IBS is complex and incompletely understood; genetics, diet and the gut microbiome are all recognized risk factors, but the part they play might be influenced by geography and culture, and hence their relative importance might vary between countries. This Review aims to provide an overview of the burden of IBS in a global context, to discuss future implications for the care of people with IBS worldwide, and to identify key areas for further research.

Knowledge and practices of primary care physicians or general practitioners treating post-infectious Irritable Bowel Syndrome

Background

Post-infectious Irritable Bowel Syndrome (PI-IBS) is a functional bowel disorder which has significant impacts to a patient’s quality of life. No IBS-specific biomarker or treatment regimen for PI-IBS currently exists, therefore understanding practice patterns and variance is of interest.

Methods

This online survey of primary care physicians and general practitioners in the USA aimed to understand the knowledge and treatment of PI-IBS within the physician’s current practice. Summary statistics are provided with a commentary on implications for practices and treatment of PI-IBS.

Results

Most physician survey respondents (n = 50) were aware of PI-IBS, but less than half discussed this condition as a possible outcome in their patients with a recent gastrointestinal infection. Most physicians indicated that they would treat the patients themselves with a focus on managing IBS through different treatment modalities based on severity. Treatment for PI-IBS followed IBS recommendations, but most physicians also prescribed a probiotic for therapy. Physicians estimated that 4 out of 10 patients who develop PI-IBS will have life-long symptoms and described significant impacts to their patient’s quality of life. Additionally, physicians estimated a significant financial burden for PI-IBS patients, ranging from $100–1000 (USD) over the course of their illness. Most physicians agreed that they would use a risk score to predict the probability of their patients developing PI-IBS, if available.

Conclusions

While this survey is limited due to sample size, physician knowledge and treatment of PI-IBS was consistent across respondents. Overall, the physicians identified significant impacts to patient’s quality of life due to PI-IBS.

Epidemiological, Clinical, and Psychological Characteristics of Individuals with Self-reported Irritable Bowel Syndrome Based on the Rome IV vs Rome III Criteria

OBJECTIVES

Few studies have examined the effects of applying the Rome IV criteria for irritable bowel syndrome (IBS) vs the previous standard, the Rome III criteria. We conducted a cross-sectional survey of individuals who self-identify as having IBS to examine this issue.

METHODS

We collected complete demographic, symptom, mood, and psychological health data from 1375 adults who self-identified as having IBS, but were not recruited from a referral population. We applied the Rome III and the Rome IV criteria simultaneously to examine what proportion met each of these diagnostic criteria for IBS. We measured the level of agreement between the Rome III and Rome IV criteria, and assessed for presence of an alternative functional bowel disorder in individuals who no longer met diagnostic criteria for IBS with the more restrictive Rome IV criteria. Finally, we compared characteristics of individuals who met only Rome III criteria with those who met Rome IV criteria.

RESULTS

In total, 1080 of 1368 individuals (78.9%) with IBS met the Rome III criteria. In contrast, 811 of 1373 individuals (59.1%) with IBS met the Rome IV criteria. Agreement between the criteria was only moderate (Kappa = 0.50). Among those who no longer had IBS according to the Rome IV criteria, 33 (11.5%) met Rome IV criteria for functional constipation, 118 (41.3%) for functional diarrhea, 68 (23.8%) for functional abdominal bloating or distension, and 67 (23.4%) for an unspecified functional bowel disorder. Individuals with Rome IV-defined IBS had more severe symptoms, and a higher proportion had a mood disorder and evidence of poor psychological health, compared with individuals who only met the Rome III criteria for IBS (P < .001).

CONCLUSIONS

The characteristics of people who believe they have IBS differ between those who meet criteria as defined by Rome IV vs Rome III, including the spectrum of disease severity. Studies are needed to determine how these changes will affect outcomes of clinical trials.

Effect of the interleukin 10 polymorphisms on interleukin 10 production and visceral hypersensitivity in Chinese patients with diarrhea-predominant irritable bowel syndrome

Background:

Irritable bowel syndrome (IBS), a functional gastrointestinal disorder, is characterized by cytokine imbalance. Previously, decreased plasma interleukin 10 (IL-10) level was reported in patients with IBS, which may be due to genetic polymorphisms. However, there are no reports correlating the IL-10 polymorphisms with IL-10 production in patients with IBS. This study aimed to analyze the effect of IL-10 polymorphisms on IL-10 production and its correlation with the clinical symptoms in Chinese patients with diarrhea-predominant IBS (IBS-D).

Methods:

Two IL-10 single nucleotide polymorphisms (rs1800871 and rs1800896) were detected in 120 patients with IBS-D and 144 healthy controls (HC) using SNaPshot. IBS symptom severity score, Bristol scale, hospital anxiety, and depressive scale (HADS) were used to evaluate the clinical symptoms, as well as the psychological status and visceral sensitivity of the subjects. IL-10 levels in the plasma and peripheral blood mononuclear cell (PBMC) culture supernatant were measured using enzyme-linked immunosorbent assay, while those in ileal and colonic mucosal biopsies were measured using immunohistochemistry.

Results:

The frequency of rs1800896 C allele was significantly lower in the patients with IBS-D than that in the HC (odds ratio: 0.49, 95% confidence interval: 0.27–0.92, P = 0.0240). The IL-10 levels in the plasma (P = 0.0030) and PBMC culture supernatant (P = 0.0500) of the CT genotype subjects were significantly higher than those in the TT genotype subjects. The CT genotype subjects exhibited a higher pain threshold in the rectal distention test than the TT genotype subjects. Moreover, IL-10 rs1800871 GG genotype subjects showed an increase in the HADS score compared to other genotype subjects.

Conclusions:

IL-10 rs1800896 C allele is correlated with higher IL-10 levels in the plasma and the PBMC culture supernatant, which is associated with a higher pain threshold in the Chinese patients with IBS-D. This study provides an explicit relationship of IL-10 polymorphisms with IL-10 production, which might help in understanding the pathogenesis of IBS-D.

Reduction in IBS symptom severity is not paralleled by improvement in quality of life in patients with irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a brain-gut disorder, of which the natural course varies between patients and is difficult to predict. This study aimed to evaluate symptom evolution over a 5-year follow-up period and to identify baseline predictors for symptom severity and quality of life (QoL) at follow-up.

METHODS

Maastricht IBS cohort participants completed questionnaires upon inclusion regarding demographics and lifestyle, gastrointestinal (GI) symptoms, anxiety and depression, and QoL. The same questionnaires, in addition to others, were completed after 5 years. Rome criteria were confirmed face-to-face at initial enrollment and through telephonic interviews at follow-up.

KEY RESULTS

At a mean follow-up of 4.7 years, 379 patients were approached of whom 203 (53.7%) responded. Of these, 161 were reached by telephone and analyzed; 49 (30.4%) did not fulfill the Rome III criteria at follow-up and had lower levels of GI symptoms and GI-specific anxiety compared to those remaining Rome III-positive (P < 0.001). However, Rome III-negative patients had comparable levels of QoL and life satisfaction, comorbid anxiety and depression, work absenteeism, and impaired productivity. No baseline predictors were found for being Rome III-positive or Rome III-negative. However, greater age and lower baseline physical QoL predicted lower physical QoL at follow-up (P < 0.005 and P < 0.01, respectively), while lower baseline mental QoL predicted lower mental QoL at follow-up (P = 0.005). Additionally, higher anxiety and depression scores at follow-up were associated with lower QoL and life satisfaction at follow-up (P < 0.001).

CONCLUSIONS AND INFERENCES

Long-term QoL and general well-being might depend on concurrent psychological symptoms, rather than GI symptom improvement.

Post-infectious Irritable Bowel Syndrome: A Narrative Review

The Irritable bowel syndrome (IBS) is a functional disorder of alimentary system, which may be caused by infectious gastroenteritis determined as post infectious irritable bowel syndrome (PI-IBS). The prevalence of PI-IBS is reported to be 4-36% in patients with infectious gastroenteritis. The exact mechanism leading to PI-IBS is not fully understood and some factors pertaining to infectious agent and host response may have a role. Rome IV diagnostic criteria provided new definition for PI-IBS. Though it is now considered a well-defined functional disorder of gastrointestinal system, no specific treatment is yet available for PI-IBS. This article reviews the latest issues on these heading about PI-IBS.