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Irritable Bowel Syndrome

Tundra lists 103 Irritable Bowel Syndrome clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.

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RECRUITING

NCT06788444

Efficacy of Esketamine for Patients With Irritable Bowel Syndrome

To explore the efficacy of a single low dose of esketamine for patients with irritable bowel syndrome (IBS).

Gender: All

Ages: 18 Years - 60 Years

Updated: 2026-08-28

1 state

Irritable Bowel Syndrome
RECRUITING

NCT07545772

A Study of Brenipatide (LY3537031) in Participants With Irritable Bowel Syndrome-Constipation (IBS-C)

The purpose of this study is to evaluate how well brenipatide (LY3537031) is tolerated what side effects may occur, and the safety and efficacy in participants with Irritable Bowel Syndrome-Constipation (IBS-C). The study drug will be administered subcutaneously (SC) (under the skin) when compared with placebo. The study will last approximately 35 weeks.

Gender: All

Ages: 18 Years - 75 Years

Updated: 2026-08-24

10 states

Irritable Bowel Syndrome
Constipation
RECRUITING

NCT07545759

A Study of Brenipatide (LY3537031) in Participants With Irritable Bowel Syndrome-Diarrhea (IBS-D)

The purpose of this study is to evaluate how well brenipatide (LY3537031) is tolerated, what side effects may occur, and the safety and efficacy in participants with Irritable Bowel Syndrome-Diarrhea (IBS-D). The study drug will be administered subcutaneously (SC) (under the skin) when compared with placebo. The study will last approximately 35 weeks.

Gender: All

Ages: 18 Years - 75 Years

Updated: 2026-08-24

11 states

Irritable Bowel Syndrome
Diarrhea
COMPLETED

NCT07774923

Dietary Interventions for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by recurrent abdominal pain and altered bowel habits. Dietary factors may trigger or worsen symptoms such as abdominal pain, bloating, gas, diarrhea, and constipation. This study evaluated and compared the effects of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (low-FODMAP) diet and a combined gluten-free and lactose-free diet on symptom severity in adults diagnosed with IBS. Adults aged 19-64 years with IBS followed one of the two dietary interventions for six weeks. IBS symptom severity was assessed at baseline and at the end of week 6 using the Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS). Dietary adherence was monitored by telephone during the intervention.

Gender: All

Ages: 18 Years - 64 Years

Updated: 2026-08-20

Irritable Bowel Syndrome
RECRUITING

NCT05972291

Mechanisms of Gulf War Illness

Many veterans with Gulf War Illness developed chronic gastrointestinal symptoms during their deployment to the Persian Gulf. The pathophysiologic mechanisms of these chronic gastrointestinal symptoms are not well understood but cause significant morbidity in veterans. Our proposed studies will provide an innovative and novel treatment trial for chronic gastrointestinal symptoms in veterans with Gulf War Illness that were deployed into war zones. Given that there are currently no specific treatments for these disorders, and that current symptomatic approaches are far from ideal, proof of principle of our trial would be an extremely important advance as it would not only have a beneficial impact on the health of many thousands of our veterans, but also it would substantially reduce the many negative economic effects of this ailment on the VA Health Care System.

Gender: All

Ages: 18 Years - 65 Years

Updated: 2026-08-19

1 state

Gulf War Illness
Irritable Bowel Syndrome
Gastrointestinal Symptoms
COMPLETED

NCT07465562

Galactol® Enzyme Supplement for Post-Prandial Abdominal Bloating in Irritable Bowel Syndrome

This multicenter, randomized, controlled clinical trial aims to evaluate the efficacy and safety of a dietary supplement containing a combination of digestive enzymes (alpha-galactosidase, beta-galactosidase, and prolyl-endopeptidase) in reducing post-prandial abdominal bloating in adults diagnosed with irritable bowel syndrome (IBS). Participants will be randomly assigned in a 1:1 ratio to receive either the enzyme supplement (Galactol®) in addition to a diet excluding foods high in FODMAPs, or the diet alone. The intervention will be administered for 14 days. The primary objective is to assess the change in the intensity of post-prandial abdominal bloating measured using a visual analogue scale (VAS). Secondary outcomes include changes in intestinal symptoms, stool consistency, bowel movement frequency, episodes of diarrhea, global gastrointestinal well-being, and treatment tolerability. The results of this study will provide evidence regarding the potential role of enzyme supplementation in reducing gastrointestinal symptoms associated with food-related fermentation in patients with IBS.

Gender: All

Ages: 18 Years - 75 Years

Updated: 2026-08-14

2 states

Irritable Bowel Syndrome
Abdominal Bloating
COMPLETED

NCT03869372

Cerebral Cortical Influences on Autonomic Function

This is an exploratory neurophysiological study that will determine the impact of non-invasive brain stimulation on autonomic regulation, with a focus on gastrointestinal function. These studies should provide a basis for future brain-based neurotherapeutic strategies in patients with functional GI disorders.

Gender: All

Ages: 21 Years - 60 Years

Updated: 2026-08-14

1 state

Healthy Subjects
Functional Dyspepsia
Irritable Bowel Syndrome
NOT YET RECRUITING

NCT07600047

A Well-Being Intervention for People With IBS

The purpose of this randomized behavioral clinical trial is to examine whether a well-being intervention can improve both psychological well-being and physical outcomes in adults with Irritable Bowel Syndrome (IBS). The study aims to assess whether this intervention decreases anger, anxiety, and depression; increases self-esteem, empathy, and hope; and improves quality of life indicators such as IBS symptom severity, sleep quality, fatigue, and diet. Participants can expect to be on study for up to 9 months.

Gender: All

Ages: 18 Years - Any

Updated: 2026-08-13

1 state

Irritable Bowel Syndrome
RECRUITING

NCT07750535

Liver Steatosis and Fibrosis in Non-Celiac Wheat Sensitivity Patients: a Prospective Study

Hypothesizing an intestinal barrier impairment as a common pathophysiological substrate of both Non Celiac Wheat Sensitivity (NCWS) and Metabolic Dysfunction-Associated Steatotic Liver Disease (MAFLD), in a retrospective cohort study (data not yet published), demographic, clinical, laboratory and histology data of NCWS patients at the time of diagnosis, were analyzed and compared to control subjects with Irritable Bowel Syndrome/Functional Dyspepsia (IBS/FD) and freshly diagnosed Celiac Disease (CeD). NCWS diagnosis was performed by a double-blind placebo-controlled wheat challenge. Steatosis was confirmed by ultrasound examination. Our retrospective data showed that the frequency of liver of steatosis was lower in NCWS than in IBS patients. In addition, it seems that pre-diagnosis avoidance of wheat in NCWS correlates with protection from steatosis. A subset of NCWS patients, recently exposed to wheat, with clinical features suggesting increased IP, seems to be predisposed to liver steatosis and fibrosis. To validate the results of the retrospective study, the researchers planned the present prospective study, to analyze the prevalence of liver steatosis and fibrosis, evaluated by ultrasound (US) examination, FibroScan analysis \[CAP (Controlled Attenuation Parameter) and LSM (Liver Stiffness Measurement) values\], FIB-4 (Fibrosis-4) index, and NFS \[Non-alcoholic fatty liver disease (NAFLD) Fibrosis Score\], in patients with NCWS at the time of diagnosis, comparing them with two control populations of newly diagnosed IBS/FD and CeD patients.

Gender: All

Ages: 18 Years - 65 Years

Updated: 2026-08-11

1 state

Metabolic Dysfunction-Associated Steatotic Liver Disease
Non Celiac Wheat Sensitivity
Irritable Bowel Syndrome
+2
RECRUITING

NCT03223077

Mucosal and Microbiota Changes During Acute Campylobacteriosis

Gastrointestinal (GI) infection with Campylobacter causes inflammation in the bowel and can change bacteria in the gut. Certain individuals with Campylobacter infection are also known to develop chronic bowel problems such as Irritable Bowel Syndrome (IBS). The researchers are doing this study to understand if changes in gut bacteria and gut mucosal lining during an acute infection can help identify individuals who might be at risk for developing problems in the future.

Gender: All

Ages: 18 Years - 80 Years

Updated: 2026-08-07

1 state

Irritable Bowel Syndrome
COMPLETED

NCT06687720

A Clinical Study to Determine the Safety and Efficacy of An Oral Probiotic Supplementation in the Management of Irritable Bowel Syndrome With Protein Digestion.

This is an open-label, two-arm, prospective, interventional, in-use safety and efficacy study of an oral probiotic supplementation in adult subjects having irritable bowel syndrome.

Gender: All

Ages: 18 Years - 60 Years

Updated: 2026-07-31

1 state

Irritable Bowel Syndrome
RECRUITING

NCT06801184

Single-center Exploratory Study of the Intestinal Microbiota in Patients Treated for Irritable Bowel Syndrome With Predominant Constipation and Methane Production

Irritable Bowel Syndrome (IBS), characterized by the Rome IV criteria, is a functional bowel disorder combining abdominal pain with changes in bowel habits and/or stool consistency. This condition is common, affecting 5% to 10% of the population in developed countries. The etiology of IBS is multifactorial, involving intestinal motility disorders, visceral hypersensitivity, micro-inflammation of the intestinal mucosa, and dysbiosis. It has been demonstrated that the sub-category of IBS patients with constipation predominantly have increased amounts of Methanobrevibacter smithii, the most common methanogenic archaea found in the intestinal lumen, compared to other IBS patients. Breath tests can evaluate methane production by the intestinal microbiota, indirectly assessing the presence and quantity of methanogenic archaea. The acronym IMO (intestinal methanogen overgrowth) defines the association of digestive symptoms (notably bloating and constipation) with a high concentration of methane in exhaled gases (≥ 10 ppm). The links between constipation, methane production, and fecal microbiota are uncertain, necessitating further studies that could lead to precise diagnostic and treatment recommendations. Main objective: Describe the initial composition of the fecal microbiota of constipated methano-producing IBS patients. Secondary objectives: 2\. Describe the initial composition of blood metabolites linked to the microbiota of constipated methano-producing IBS patients 3. Describe the evolution of the fecal microbiota and blood metabolites linked to the fecal microbiota during conventional therapeutic management (before and after) of constipated methano-producing IBS patients. 4\. Compare the composition of the fecal microbiota before and after conventional therapeutic management of responding IBS-C patients (-30% on the IBS-SSS symptom severity score) compared to non-responding patients. 5\. Evaluate the impact of Methanobrevicter smithii in the response to symptomatic treatment. Exploratory observational single-center study (cohort follow-up) descriptive in patients with irritable bowel syndrome with constipation (IBS-C, IBS-m or IBS-U) with excessive methane production detected on a glucose breath test. Patients will be invited to participate once the results of the breath test are known. Please note: In the context of this study, only two microbiota samples and 4 additional tubes and one tube of blood will be added to the usual practice. All treatments will be prescribed as part of the care and are not conditioned by the research protocol. The primary endpoint is the analysis of the initial composition (16S rRNA gene sequencing) of the fecal microbiota of constipated methano-producing IBS patients. The study population consists of constipated IBS patients with excessive methane production seen in the digestive functional exploration department for a breath test prescribed as part of an external procedure or a day hospital session. A total of 40 patients will be included over 18 months, with a participation duration of 2 months +/- 2months per subject. Patients with IBS constitute a heterogeneous population for whom only symptomatic treatment is currently offered with variable and unpredictable efficacy. Through this work, we seek to find new therapeutic axes to relieve or even treat their symptoms.

Gender: All

Ages: 18 Years - Any

Updated: 2026-07-27

Irritable Bowel Syndrome
NOT YET RECRUITING

NCT07716852

Enzymax DuoBiotics for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by recurrent abdominal pain associated with altered bowel habits in the absence of detectable structural abnormalities. Its pathophysiology is multifactorial and may involve alterations in the intestinal microbiota, impaired epithelial barrier function, low-grade immune activation, and disturbances in the digestion and fermentation of dietary nutrients. Enzymax DuoBiotics combines digestive enzymes with a synbiotic formulation in a capsule-in-capsule delivery system. The outer capsule contains digestive enzymes intended for release in the stomach, whereas the inner capsule contains Lactobacillus plantarum and fructooligosaccharides intended for release in the intestine. This formulation is designed to separate the enzymatic and synbiotic components and support their delivery to the intended gastrointestinal sites. The combined approach is intended to support macronutrient digestion while modulating the intestinal microbial environment. This randomized, double-blind, placebo-controlled, parallel-group study will compare once-daily Enzymax DuoBiotics with placebo over a 12-week treatment period in adults with IBS. Participants will be allocated in a 1:1 ratio, and treatment effects over time will be evaluated using assessments performed during the treatment period. The primary statistical analysis will use linear mixed-effects models including treatment group, time, and the treatment group-by-time interaction. The primary analysis will follow the intention-to-treat principle and may be supplemented by a per-protocol analysis.

Gender: All

Ages: 18 Years - 70 Years

Updated: 2026-07-23

Irritable Bowel Syndrome
Irritable Bowel Syndrome (IBS)
NOT YET RECRUITING

NCT06706778

The Mechanism Underlying the Analgesic Effect of the Music of IBS Pain

The proposed pilot study aims to assess the underlying mechanisms of the MBI on IBS pain and the feasibility of using novel technology in the outcome measurements. The specific aims of this pilot mechanistic clinical trial are to: 1. . identify the mechanisms underlying the impact of MBI on IBS-related pain, stress responses, quantitative pain sensitivity, and gut microbiome profiles. 2. . evaluate the technological feasibility of using a wearable abdominal sensor belt and smartwatch system in measuring MBI impacts on pain in home settings. Researchers will conduct a one-arm pre- and post-music intervention among patients with Irritable Bowel Syndrome, collect the IBS pain mechanistic biobehavioral markers, and analyze the underlying pathways of the music analgesic effect. Participants will be asked to: 1. . engage in a 4-week intervention of 20 minutes, both during the day and at night, for at least five days per week. 2. . have two one-hour lab visits

Gender: All

Ages: 18 Years - 50 Years

Updated: 2026-07-02

1 state

Abdominal Pain/ Discomfort
Irritable Bowel Syndrome
RECRUITING

NCT06413004

Brachyspira and Intestinal Allergy-like Immune Reactions in Patients With Irritable Bowel Syndrome (IBS)

The aim of this study is to define local immune responses in the GI tract to food antigens in IBS patients, with and without Brachyspira infection, using advanced imaging. We hypothesize that Brachyspira infection can cause IBS symptoms by inducing loss of oral tolerance to dietary antigens through development of food-specific intestinal immune reactions and subsequent development of visceral hypersensitivity. During this study, the investigators will perform confocal laser endomiscroscopy (CLE) and/or colonoscopic antigen provocation test (COLAP) to test to which food items the participants react to. Furthermore, the investigators will perform rectal barostat examination and a sigmoidoscopy without laxatives. The investigators will collect biological samples and the participants will complete several questionnaires.

Gender: All

Ages: 18 Years - 70 Years

Updated: 2026-06-29

Irritable Bowel Syndrome
Food Sensitivity
RECRUITING

NCT07519395

A Study to Investigate Abdominal Symptoms With Camlipixant Compared With Placebo in Adults With Irritable Bowel Syndrome - Diarrhea (IBS-D) and Irritable Bowel Syndrome - Mixed (IBS-M)

This study is designed to evaluate the efficacy and safety of camlipixant in adults with IBS-D and IBS-M. The study has two parts. After the first part, some participants will be randomly chosen again to either get a higher dose or stop the drug.

Gender: All

Ages: 18 Years - 80 Years

Updated: 2026-06-25

23 states

Irritable Bowel Syndrome
COMPLETED

NCT06268717

GI Alpha-Gal Study

This is a double-blind, crossover food challenge study using pork with and without α-gal in patients with a clinical diagnosis of gastrointestinal (GI)- α-gal allergy, and to investigate the pathophysiology underlying their symptoms.

Gender: All

Ages: 18 Years - 99 Years

Updated: 2026-06-23

1 state

Alpha-Gal Syndrome
Irritable Bowel Syndrome
Diarrhea
+2
RECRUITING

NCT06866106

Well-being in IBS: Strengths and Happiness (WISH) 2.0

The purpose of this study is to examine the feasibility, acceptability, preliminary effects, and candidate gut-brain mechanisms of an optimized positive psychology (PP) intervention for patients with irritable bowel syndrome (IBS), entitled "WISH," compared to an educational control intervention.

Gender: All

Ages: 18 Years - Any

Updated: 2026-06-22

1 state

Irritable Bowel Syndrome
RECRUITING

NCT07494968

Defining Objective Markers of Compliance for Dietary Therapies in IBS

This research will investigate if a specific marker in your stool or urine can be used to track changes in your carbohydrate intake including fructo-oligosaccharide and mannitol intake

Gender: All

Ages: 18 Years - 65 Years

Updated: 2026-06-22

1 state

Irritable Bowel Syndrome
RECRUITING

NCT05972317

The Stool Microbiome of Treated and Untreated IBS (Irritable Bowel Syndrome) Patients

Irritable bowel syndrome (IBS) is considered the most common gastrointestinal disorder in humans, with an estimated global prevalence of 11%-20% of all humans. Alterations in the gut microbiome are at the center of IBS, and microbiome-induced volatile metabolites in response to dietary exposures is believed to drive a downstream impact on susceptible hosts, thereby driving the disease. However, the characteristics and functions of these metabolites remain unknown to date. The two main mechanisms invoking IBS development and flares include 1) an increase in luminal water content due to malabsorption of small molecules and 2) incrementation of colon gas production generated by the fermentation of small molecules by gut bacteria.Yet to date, a person-specific elucidation of the specific small molecules and bacteria driving IBS, and their downstream effects on the human gut epithelium remain unknown. Over the past years, it became evident that dietary regimes, and their interactions with the intestinal microbiome, are at the center of IBS symptom generation and alleviation. The most widely used dietary intervention is a highly restrictive diet, the low-Fermentable Oligo-saccharides Di-saccharides Mono-saccharides And Polyols (FODMAP) diet, based on avoidance of multiple food items that contain available fermentable molecules. The low-FODMAP diet remains an effective line of treatment for IBS patients, yet due to its complexity and unhealthy nature, it remains a last line of treatment and fails to impact the majority of IBS patients.

Gender: All

Ages: 18 Years - 70 Years

Updated: 2026-06-11

Irritable Bowel Syndrome
COMPLETED

NCT07607132

Digitally Delivered Dietary Treament for Adult Patients With Irritable Bowel Syndrome: A Pilot Study

Two carbohydrate reduced diets, the low FODMAP diet (LFD) and low-carbohydrate diet (LCD), have in randomized controlled studies shown efficacy in relieving symptoms in patients with Irritable Bowel Syndrome (IBS), but access to trained dieticians is limited. Digital delivery may offer a convenient, cost-effective and scalable solution. This pilot study aims to evaluate the effectiveness and feasibility of digitally delivered evidence-based dietary treatments in relieving gastrointestinal, psychological and somatic symptoms and improving quality of life in patients with IBS. Adults with IBS will be recruited via social media and clinical referrals and will receive their choice of the two dietary treatments: LFD with traditional IBS dietary advice or LCD. Participants will get access to the digital platform which contains information about the study, IBS pathophysiology, the treatment diet along with recipes and a mobile application for food scanning. Participants will complete digital questionnaires at baseline and week four to evaluate changes in gastrointestinal symptoms (IBS-SSS), somatic and psychological symptoms (PHQ-15, HADS, VSI) and quality of life (IBS-QoL). Feasibility and adherence is assessed with an evaluation questionnaire.

Gender: All

Ages: 18 Years - 64 Years

Updated: 2026-05-28

Irritable Bowel Syndrome
RECRUITING

NCT06639984

Psyllium in Pediatric IBS

The goal of this clinical trial is to learn if a fiber (psyllium) can change the way bacteria use fructans (a type of sugar) and whether psyllium can help decrease childhood irritable bowel syndrome (IBS) symptoms when eating fructans. The main questions it aims to answer are: Aim 1: The effect of psyllium at two doses given with a fructan meal on microbial fructan fermentation (intracolonic pH; H2 gas production; gut microbiome composition; fecal short-chain fatty acids, lactate, glycomics). Aim 2: Determine the impact of psyllium given with a fructan meal on fructan-induced GI symptoms. Participants will first be asked to eat a specific diet over two three-day periods to determine if fructans worsen their IBS symptoms. Those with worsening symptoms with fructans will be asked to participate in the second part of the study. This includes two weeks of baseline (no change in diet) and two weeks of eating a specific diet with fructans with either psyllium or glucose. Participants will be asked to complete pain and stool diaries, submit stool specimens, swallow a pill to capture gut acid levels, and give breath samples.

Gender: All

Ages: 12 Years - 17 Years

Updated: 2026-05-26

1 state

Irritable Bowel Syndrome
RECRUITING

NCT06271538

Evaluation of Efficacy of Skål Pro Powder on Symptoms of Irritable Bowel Syndrome

The objective of this randomized, double-blind, placebo-controlled study is to evaluate the effectiveness of Skal Pro in alleviating symptoms, enhancing stool consistency, improving quality of life, and addressing psychological distress in individuals diagnosed with irritable bowel syndrome (IBS), as compared to those who receive no intervention.

Gender: All

Ages: 18 Years - Any

Updated: 2026-05-12

1 state

Irritable Bowel Syndrome
Gastrointestinal Diseases
Colonic Diseases, Functional
+5
RECRUITING

NCT05776914

Fecal Microbiota Transplantation for IBS

The purpose of this study is to learn the efficacy and safety of fecal microbiota transplantation (FMT) using stool from a donor with low proteolytic activity and containing the bacteria Alistipes putredinis in patients with irritable bowel syndrome (IBS) and high proteolytic activity. Proteolytic activity is the breakdown of proteins into smaller polypeptides or amino acids.

Gender: FEMALE

Ages: 18 Years - 70 Years

Updated: 2026-05-08

1 state

Irritable Bowel Syndrome
Diarrhea