Development and validation of a simple and multifaceted instrument, Chronic Constipation-Therapeutic Efficacy and Satisfaction Test (CC-TEST), for the clinical evaluation of the patients with chronic constipation.

INTRODUCTION: This study evaluated the psychometric properties of the newly developed chronic constipation therapeutic efficacy and satisfaction test (CC-TEST) among patients with chronic constipation. METHODS: Japanese patients with moderate or severe chronic constipation underwent a four-week remedy. The baseline, 2-week, and 4-week assessments included the CC-TEST, Constipation Scoring System (CSS), Medical Outcome Study Short Form-8 Health Survey (SF-8), and Hospital Anxiety and Depression Scale (HADS). The CC-TEST comprises three domains: (1) symptoms; chronic constipation symptom severity (seven items), defecation status (five items), (2) impact for daily life; dissatisfaction with daily life level (DS; four items), and (3) therapeutic response; therapeutic efficacy measured by patients and medication compliance (four items). RESULTS: Of 201 eligible patients at baseline, 110 completed the 4-week treatment and the survey responses. Cronbach's α values for the stool, defecation, and abdominal symptom subscales, as well as the total symptom score and DS subscale, showed good internal consistency reliability (0.72 - 0.80). Pearson's r for comparisons between corresponding items (CC-TEST symptoms with CSS, and CC-TEST DS with SF-8 physical and mental component summary scores) was significant. After 4 weeks, scores for symptoms, defecation status, and DS items/subscales notably decreased, with a significant effect size (P < 0.005, Cohen's d; 0.30-1.16). Statistically significant differences emerged between treatment responders and non-responders using the three responder definitions, in changes in scores for most CC-TEST symptoms, defecation status, and DS items/subscales (P < 0.05). CONCLUSION: CC-TEST demonstrates commendable reliability, convergent and known-group validity, and responsiveness to treatment effects. As a simple, comprehensive, and versatile patient-reported outcome measure, CC-TEST may be well suited for clinical trials and primary care of Japanese patients with chronic constipation.

Regulatory T cells Are Increased and Correlate With Mast Cells in Eosinophilic Esophagitis.

Background/Aims: The incidence of eosinophilic esophagitis (EoE) has been increasing recently. The role of regulatory T cells (Tregs) and correlations with other inflammatory cells in EoE remain unknown. We aim to clarify the role of Tregs and their correlations with inflammatory cells in EoE patients. Methods: Biopsies from controls and EoE patients before and after treatments were analyzed. Eosinophil infiltration was evaluated by hematoxylin and eosin staining. Immunohistochemical staining was performed to examine infiltration of T cells, Tregs, and mast cells. Gene expressions of chemokines were evaluated by reverse transcription-quantitative polymerase chain reaction. Results: Tregs and mast cells were increased in the esophageal epithelial layers of EoE patients. After treatments, Tregs and mast cells were decreased when histologic remission was achieved. Infiltration of Tregs correlated significantly with numbers of eosinophils and mast cells. Filaggrin mRNA was decreased in patients with EoE before treatment and upregulated after treatment, even when histologic remission was not achieved. Conclusions: Tregs were increased in esophageal epithelium of patients with EoE, and correlated with mast cell infiltration.

Functional Dyspepsia: Current Understanding and Future Perspective.

BACKGROUND: Functional dyspepsia (FD) is a common disorder characterized by chronic or recurrent upper abdominal pain or discomfort without any structural abnormalities in the gastrointestinal tract. FD is categorized into two subgroups based on symptoms: postprandial distress syndrome (PDS) and epigastric pain syndrome. SUMMARY: The pathophysiology of FD involves several mechanisms. Delayed gastric emptying is observed in approximately 30% of FD patients but does not correlate with symptom patterns or severity. Impaired gastric accommodation is important in the pathophysiology, particularly for PDS. Visceral hypersensitivity, characterized by heightened sensitivity to normal activities, contributes to the perception of discomfort or pain in FD. Alterations to the duodenal mucosa, including impaired mucosal barrier function and low-grade inflammation, are also implicated in the pathogenesis of FD. Microbial dysbiosis and psychological factors such as stress can further exacerbate symptoms. Treatment options include dietary modifications, establishing a physician-patient relationship, acid suppressants, prokinetics, neuromodulators, and behavioral therapies. Dietary recommendations include eating smaller, more frequent meals, and avoiding trigger foods. Acid suppressants are used as the first-line treatment. Prokinetics and neuromodulators aim to improve gastric motility and central pain processing, respectively. Behavioral therapies, including cognitive behavioral therapy and hypnotherapy, have shown benefits for refractory FD. Severe and refractory cases may require combination therapies or experimental treatments. KEY MESSAGES: FD is a disorder of gut-brain interaction involving diverse pathophysiological mechanisms. Individualized treatment based on symptoms and responses to interventions is crucial. Further research is needed to improve the understanding of FD and advance the development of effective therapies.

Pegfilgrastim for the management of neutropenia during neoadjuvant chemotherapy with docetaxel, cisplatin, and 5-fluorouracil in esophageal cancer patients.

BACKGROUND: Neoadjuvant docetaxel, cisplatin, and 5-fluorouracil (DCF) therapy is a new standard for locally advanced esophageal squamous cell carcinoma. The optimal timing of pegfilgrastim with the DCF regimen to prevent febrile neutropenia (FN) remains controversial. The effectiveness of concomitant pegfilgrastim administration with continuous 5-fluorouracil (5-FU) infusion in the DCF regimen was therefore assessed. METHODS: All patients who received neoadjuvant DCF for esophageal cancer were retrospectively assessed. Patients who had been scheduled to receive pegfilgrastim on days 3-5 (early group) or days 7-9 (regular group) of the DCF regimen were included. Uni- and multivariate analyses were used to assess risk factors for FN. RESULTS: Eighty-eight patients were included in the analysis. The 26 patients in the early group received pegfilgrastim as scheduled. In the 62 patients of the regular group, 51 received pegfilgrastim at a median of 7 days after starting DCF chemotherapy. However, 11 patients in the regular group could not receive pegfilgrastim. Twenty-two patients of the regular group and 2 patients of the early group developed FN after the first session of DCF. Early administration of pegfilgrastim and grade 4 neutropenia were significantly associated with onset of FN, with multivariate analysis identifying early administration of pegfilgrastim as an independent preventive factor and grade 4 neutropenia as a risk factor, after adjusting for sex and age. CONCLUSION: Early pegfilgrastim administration is a safe approach that reduces the incidence of FN in DCF therapy. Using pegfilgrastim with continuous 5-FU infusion in the DCF regimen represents a reasonable option to prevent FN.

Non-cardiac Chest Pain in Japan: Prevalence, Impact, and Consultation Behavior - A Population-based Study.

Background/Aims: Non-cardiac chest pain (NCCP) is defined as recurring angina-like retrosternal chest pain of non-cardiac origin. Information about the epidemiology of NCCP in Japan is lacking. We aim to determine the prevalence and characteristics of NCCP in the Japanese general population. Methods: Two internet-based surveys were conducted among the general population in March 2017. Questions investigated the characteristics of symptoms associated with chest pain and consultation behavior. Quality of life, anxiety, depression, and gastroesophageal reflux disease were analyzed. Results: Five percent of the survey respondents reported chest pain. Subjects with chest pain showed higher frequencies of anxiety and depression and lower quality of life. Among subjects with chest pain, approximately 30% had sought medical attention for their symptoms. Among all consulters, 70% were diagnosed with NCCP. Females were less likely to seek consultations for chest pain than males. Further, severity and frequency of chest pain, lower physical health component summary score, and more frequent gastroesophageal reflux disease were associated with consultation behavior. Subjects with NCCP and cardiac chest pain experienced similar impacts on quality of life, anxiety, and depression. Among subjects with NCCP, 82% visited a primary-care physician and 15% were diagnosed with reflux esophagitis. Conclusions: The prevalence of chest pain in this sample of a Japanese general population was 5%. Among all subjects with chest pain, less than one-third consulted physicians, approximately 70% of whom were diagnosed with NCCP. Sex and both the severity and frequency of chest pain were associated with consultation behavior.

Effect of Bifidobacterium bifidum G9-1 on the Intestinal Environment and Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D)-like Symptoms in Patients with Quiescent Crohn's Disease: A Prospective Pilot Study.

Diarrhea-predominant irritable bowel syndrome (IBS-D)-like symptoms are distressing for patients with quiescent Crohn's disease (qCD) and worsen their quality of life. In the present study, we assessed the effect of the probiotic Bifidobacterium bifidum G9-1 (BBG9-1) on the intestinal environment and clinical features in patients with qCD. Eleven patients with qCD, who met the Rome III diagnostic criteria for IBS-D, received BBG9-1 (24 mg) orally three times daily for 4 weeks. Indices of the intestinal environment (fecal calprotectin level and gut microbiome) and clinical features (CD/IBS-related symptoms, quality of life and stool irregularities) were evaluated before and after treatment. Treatment with BBG9-1 tended to reduce the IBS severity index in the studied patients (p = 0.07). Among gastrointestinal symptoms, abdominal pain and dyspepsia tended to be improved by the BBG9-1 treatment (p = 0.07 and p = 0.07, respectively), and IBD-related QOL showed a significant improvement (p = 0.007). With regard to mental status, the patient anxiety score was significantly lower at the endpoint of BBG9-1 treatment than at the baseline (p = 0.03). Although BBG9-1 treatment did not affect the fecal calprotectin level, it suppressed the serum MCP-1 level significantly and increased the abundance of intestinal Bacteroides in the study patients. The probiotic BBG9-1 is able to improve IBD-related QOL with a reduction of anxiety score in patients with quiescent CD and IBS-D-like symptoms.

Diarrhea-predominant Irritable Bowel Syndrome-like Symptoms in Patients With Quiescent Crohn's Disease: Comprehensive Analysis of Clinical Features and Intestinal Environment Including the Gut Microbiome, Organic Acids, and Intestinal Permeability.

Background/Aims: Diarrhea-predominant irritable bowel syndrome (IBS-D)-like symptoms frequently occur in patients with quiescent Crohn's disease (CD). To investigate the factors underlying IBS-D-like symptoms in patients with quiescent CD, we performed a comprehensive analysis of the clinical features and intestinal environment in those patients. Methods: We performed a prospective observational study of 27 patients with quiescent CD (CD activity index [CDAI] ≤ 150; C-reactive protein ≤ 0.3 mg/dL). The presence and severity of IBS-D-like symptoms, health-related quality of life, disease-specific quality of life, and status of depression and anxiety were evaluated. The level of intestinal permeability, fecal calprotectin and organic acids and the profiles of gut microbiome were analyzed. Results: Twelve of the 27 patients with quiescent CD (44.4%) had IBS-like symptoms, and these patients showed a significantly higher CDAI, IBS severity index and anxiety score than those without. The inflammatory bowel disease questionnaire score was significantly lower in the patients with IBS-D-like symptoms. There were no significant differences in small intestinal/colonic permeability or the levels of organic acids between the patients with and without IBS-D-like symptoms. Fusicatenibacter was significantly less abundant in the patients with IBS-D-like symptoms whereas their fecal calprotectin level was significantly higher (384.8 ± 310.6 mg/kg) than in patients without (161.0 ± 251.0 mg/kg). The receiver operating characteristic curve constructed to predict IBS-D-like symptoms in patients with quiescent CD using the fecal calprotectin level (cutoff, 125 mg/kg) showed a sensitivity and specificity of 73.3% and 91.7%, respectively. Conclusion: Minimal inflammation is closely associated with the development of IBS-D-like symptoms in patients with quiescent CD.

Efficacy of Serotonin Type 3 Receptor Antagonist Ramosetron on Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D)-Like Symptoms in Patients with Quiescent Inflammatory Bowel Disease: A Randomized, Double-Blind, Placebo-Controlled Trial.

Patients with quiescent inflammatory bowel disease (IBD) frequently suffer diarrhea-predominant irritable bowel syndrome (IBS-D)-like symptoms, such as abdominal pain or stool irregularities. Here, we assessed the effect of ramosetron, a serotonin type 3 (5-HT3) receptor antagonist, on IBS-D-like symptoms in patients with quiescent IBD. Seventy patients with quiescent IBD, who met the Rome III diagnostic criteria for IBS-D, were randomly assigned to receive either ramosetron (5 µg; n = 35) or a placebo (n = 35) orally once daily for 4 weeks. The primary endpoint was the responder rate for global assessment of relief from overall IBS-D-like symptoms. The responder rates for relief of abdominal pain/discomfort and improvement of bowel habits were also evaluated. The responder rate for relief from overall IBS-D-like symptoms at the final evaluation point was significantly higher in the ramosetron group (35.5%) than in the placebo group (11.4%) (p = 0.037). The responder rate for improvement of bowel habits was significantly higher in the ramosetron group (38.7%) than in the placebo group (14.3%) (p = 0.028). The reduction of stool frequency was significantly greater in the ramosetron group than in the placebo group (p = 0.044). Ramosetron is effective for relief of overall IBS-D-like symptoms in patients with quiescent IBD.

Esophageal Mucosal Permeability as a Surrogate Measure of Cure in Eosinophilic Esophagitis.

This study aimed to evaluate the relationship of esophageal epithelial permeability with mast cell infiltration and IgG4 deposits as well as chemokine levels in eosinophilic esophagitis (EoE) patients before and after treatment. Biopsies from controls and EoE patients before and after treatment were analyzed. Hematoxylin and eosin staining was used to show eosinophil infiltration. Paracellular permeability of the esophageal epithelium was assessed using surface biotinylation. Immunohistochemical staining was performed to examine mast cell infiltration and IgG4 deposits. Gene expression of chemokines was evaluated by qRT-PCR. Esophageal epithelial infiltration of mast cells, IgG4 deposits, and permeability were significantly increased in EoE patients. Levels of interleukin-13, calpain-14, and eotaxin-3 mRNAs were significantly upregulated, while filaggrin, serine peptidase inhibitor Kazal type 7 (SPINK7), and involucrin mRNAs were significantly downregulated in EoE patients. In patients achieving histologic remission diagnosed by eosinophil counts, a subset of EoE patients with unchanged permeability after treatment showed increases in mast cell infiltration, IgG4 deposits, and interleukin-13, calpain-14, filaggrin, and SPINK7 expression, with decreased eotaxin-3 and involucrin. Other EoE patients with decreased permeability displayed decreased eotaxin-3, involucrin, and mast cell infiltration, no IgG4 deposits, and increased IL-13, calpain-14, filaggrin, and SPINK7. Increased permeability of the esophagus in EoE patients without eosinophil infiltration after treatment was associated with mast cell infiltration and IgG4 deposits.

Epidemiology and Clinical Characteristics Based on the Rome III and IV Criteria of Japanese Patients with Functional Dyspepsia.

The subtypes of functional dyspepsia (FD) differ depending on whether the Rome III criteria or the Rome IV criteria are used. We investigated the ability to diagnose FD patients using the Rome III and IV criteria. The subtypes of FD were evaluated using the Rome questionnaire. The Gastrointestinal Symptom Rating Score, health-related quality of life (HR-QOL; SF-8), and psychological scores (HADS, STAI) were evaluated. The questionnaire was collected from a total of 205 patients, and 54.1% were FD patients. The ratio of FD patients under the Rome III criteria was 19% for epigastric pain syndrome (EPS), 38% for postprandial distress syndrome (PDS), and 43% for an overlap of EPS and PDS, but under the Rome IV criteria overlap decreased to 17% and PDS increased to 64%. Patients whose subtype changed from overlap under the Rome III criteria to PDS under the Rome IV criteria were compared with PDS patients whose subtype did not change between the Rome III and IV criteria. The comparison showed that the former had significantly lower early satiation rates and significantly higher acid reflux and abdominal pain scores, demonstrating that EPS symptoms due to acid reflux after meals were clearly present. As a result of changing from the Rome III criteria to the Rome IV criteria, the number of overlap patients decreased, and the number of PDS patients increased.

Network Meta-analysis Comparing Vonoprazan and Proton Pump Inhibitors for Heartburn Symptoms in Erosive Esophagitis.

GOALS: This systematic review and network meta-analysis aimed to assess the relative efficacy of vonoprazan and proton pump inhibitors (PPIs) on early heartburn symptom resolution in patients with erosive esophagitis. BACKGROUND: Limited available data directly compare the efficacy of vonoprazan, a first-in-class potassium-competitive acid blocker, with PPIs in erosive esophagitis. STUDY: We conducted a systematic literature review (in MEDLINE and CENTRAL) and subsequent network meta-analysis according to Cochrane and PRISMA guidelines. Double-blind, randomized controlled trials in adults with erosive esophagitis treated with vonoprazan or a PPI were included in the analysis. Primary outcomes were heartburn symptom resolution rate on Day 1 and Day 7. The study was performed with all available data, using a random effects model within a Bayesian framework. RESULTS: Overall, 10 randomized controlled trials were included in the network meta-analysis. For heartburn resolution rate on Day 1 (9 of 10 trials), vonoprazan 20 mg once daily (QD) was superior to placebo (median odds ratio=16.75, 95% credible interval: 2.16-207.80). Point estimates numerically favored vonoprazan 20 mg QD over other comparators. For heartburn resolution rate on Day 7 (10 of 10 trials), vonoprazan 20 mg QD was superior to placebo and other comparators except rabeprazole 20 mg QD. Point estimates numerically favored vonoprazan 20 mg QD over rabeprazole 20 mg QD. CONCLUSIONS: In this study, vonoprazan 20 mg QD was equally effective in heartburn resolution on Day 1, and equally or more effective on Day 7 versus PPIs in adults with erosive esophagitis.

Yokukansan Suppresses Gastric Hypersensitivity and Eosinophil-associated Microinflammation in Rats With Functional Dyspepsia.

Background/Aims: Herbal medicine is an important complementary therapy for functional dyspepsia (FD). However, its effect against gastric hypersensitivity in patients with FD has rarely been evaluated. Yokukansan (YKS), a traditional Japanese herbal medicine, is effective against neuropathic and inflammatory pain. This study aims to use a maternal separation (MS) stress-induced FD model to investigate the effects of YKS against gastric hypersensitivity, gastric motility, and duodenal micro-inflammation. Methods: The MS stress model was established by separating newborn Sprague-Dawley rats from their mothers for 2 hours a day from postnatal days 1 to 10. At the age of 7-8 weeks, the rats were treated with YKS at a dose of 5 mL/kg (1 g/kg) for 7 consecutive days. After YKS treatment, electromyographic activity in the acromiotrapezius muscle by gastric distention and the gastric-emptying rate were assessed. Immunohistochemical analysis of eosinophils in the duodenum and phosphorylated extracellular signal-regulated kinase (p-ERK) 1/2 in the spinal cord was performed. Results: YKS treatment suppressed MS stress-induced gastric hypersensitivity and decreased the elevated levels of p-ERK1/2 in the spinal cord. In the gastroduodenal tract, YKS inhibited eosinophil-associated micro-inflammation but did not improve gastric dysmotility. Conclusions: YKS treatment improved gastric hypersensitivity by alleviating eosinophil-associated micro-inflammation in the gastroduodenal tract. This treatment may be considered an effective therapeutic option for epigastric pain and micro-inflammation in patients with FD.

Duodenal cholinergic tuft cell number is increased in functional dyspepsia.

BACKGROUND: Low-grade duodenal inflammation has recently been identified in patients with functional dyspepsia (FD). Chemosensory tuft cells were reported to be associated with gastrointestinal diseases. We therefore assessed duodenal tuft cell density and microinflammation in patients with FD to determine whether these measures could serve as useful biomarkers, and also correlated tuft cell density and microinflammation in FD patients. METHODS: Duodenal biopsy specimens were obtained from patients with FD and from controls. Tuft cells, eosinophils, and mast cells were immunochemically stained with specific antibodies. Tuft cells were identified by immunostaining for doublecortin-like kinase 1 (DCLK1); cholinergic tuft cells were assessed by double staining for choline acetyltransferase (ChAT) and DCLK1. Immune-type tuft cells were assessed by IL-25 mRNA expression using real-time PCR. KEY RESULTS: The density of intramucosal eosinophils and mast cells was significantly higher in the duodenum of FD patients than in controls. The density of tuft cells was significantly higher in the duodenum of FD patients compared with controls, and significantly correlated with eosinophil density in the duodenum of FD patients and controls. Moreover, a fraction of ChAT-positive cells was DCLK1 positive; all duodenal DCLK1+ tuft cells were ChAT-immunoreactive in FD and in control subjects. CONCLUSIONS AND INFERENCES: Cholinergic tuft cell density was higher in the duodenum of patients with FD and significantly correlated with eosinophil density. Further studies are needed to investigate the pathophysiological significance of tuft cells in FD and may provide valuable clues to the pathophysiology of FD.

Evidence-based clinical practice guidelines for functional dyspepsia 2021.

BACKGROUND: Functional dyspepsia (FD) is a disorder that presents with chronic dyspepsia, which is not only very common but also highly affects quality of life of the patients. In Japan, FD became a disease name for national insurance in 2013, and has been gradually recognized, though still not satisfactory. Following the revision policy of Japanese Society of Gastroenterology (JSGE), the first version of FD guideline was revised this time. METHOD: Like previously, the guideline was created by the GRADE (grading of recommendations assessment, development and evaluation) system, but this time, the questions were classified to background questions (BQs, 24 already clarified issues), future research questions (FRQs, 9 issues cannot be addressed with insufficient evidence), and 7 clinical questions that are mainly associated with treatment. RESULTS AND CONCLUSION: These revised guidelines have two major features. The first is the new position of endoscopy in the flow of FD diagnosis. While endoscopy was required to all cases for diagnosis of FD, the revised guidelines specify the necessity of endoscopy only in cases where organic disease is suspected. The second feature is that the drug treatment options have been changed to reflect the latest evidence. The first-line treatment includes gastric acid-secretion inhibitors, acetylcholinesterase (AChE) inhibitors (acotiamide, a prokinetic agent), and Japanese herbal medicine (rikkunshito). The second-line treatment includes anxiolytics /antidepressant, prokinetics other than acotiamide (dopamine receptor antagonists, 5-HT4 receptor agonists), and Japanese herbal medicines other than rikkunshito. The patients not responding to these treatment regimens are regarded as refractory FD.

Acid increases PGE2 in the duodenal mucosa in rats.

Attention has recently been paid to the duodenum as the pathophysiologic center of functional dyspepsia. However, the precise mechanisms of symptom generation remain unknown. We here investigated the effect of acid on duodenal prostaglandin E2 and localization of prostaglandin E2 related receptors. Sprague-Dawley rats were used for this study. Hydrochloric acid was administered in the duodenum, then prostaglandin E2 levels in the duodenum were measured using the ELISA. The expression and localization of prostaglandin receptors (EP1-4) and the mRNAs of prostaglandin synthases were investigated using in situ hybridization histochemistry in duodenal tissue. After acid perfusion, prostaglandin E2 levels in the duodenum significantly increased. EP3 was expressed mainly at the myenteric plexus in the duodenal mucosa, and EP4 at both the epithelial surface and myenteric plexus. Contrary, EP2 was sparsely distributed in the villi and EP1 were not clearly seen on in situ hybridization histochemistry. Prostaglandin-synthetic enzymes were also distributed in the duodenal mucosa. The prostaglandin E2 levels in the duodenum increased after acidification. Prostaglandin E2 receptors and prostaglandin E2-producing enzymes were both observed in rat duodenum. These observations suggest that duodenal prostaglandin E2 possibly play a role in the symptom generation of functional dyspepsia.

Microinflammation in the intestinal mucosa and symptoms of irritable bowel syndrome.

BACKGROUND: Potential etiological mechanisms of irritable bowel syndrome (IBS) have been reported, and emerging data suggest that immune activation is present in a major subset of IBS, especially in those with diarrhea. Intestinal mucosal mast cell and intraepithelial lymphocyte (IEL) infiltration and related factors were examined in patients with IBS. In addition, the correlations of symptoms and micro-inflammation were assessed. METHODS: Intestinal biopsy specimens were obtained from patients with IBS and controls. Mast cells and IELs were stained with specific antibodies. The mRNA levels of cytokines and chemokines were assessed by quantitative reverse transcription polymerase chain reaction. RESULTS: Infiltration of mast cells in the duodenum was significantly higher in IBS patients than in control subjects. The infiltration of IELs was higher in the duodenum and terminal ileum of IBS patients compared to the control subjects. The numbers of duodenal and ileal IELs were significantly correlated. The number of IELs but not mast cells in the duodenum and terminal ileum was significantly correlated with diarrhea frequency in control subjects and IBS patients. The expression level of the chemotactic chemokine CXCL11 was significantly higher in the duodenum of IBS patients. CONCLUSION: Duodenal mast cells and IELs were increased in IBS patients. In addition, a positive correlation was found between the number of duodenal and ileal IELs and the frequency of diarrhea. Given that the present study was strictly observational, further studies are needed to clarify the pathophysiological functions associated with micro-inflammation in IBS.