Irritable bowel syndrome affects about 10-15% of adults worldwide, causing recurring abdominal pain, bloating, and changes in bowel habits. Treatment typically starts with diet changes, fiber, and medications for diarrhea or constipation, though many people continue to have symptoms. Research is now exploring the gut-brain connection, microbiome changes, and immune activation in IBS.
What's actually going on in research
Trials are testing drugs that target gut serotonin receptors, bile acid modulators, gut-selective antibiotics, and microbiome therapies including specific bacterial strains. Researchers are also studying how the brain and gut communicate in IBS, testing neuromodulators and gut-directed psychological treatments. Some trials focus on post-infection IBS and immune changes in the gut lining.
Microbiome-targeted therapies
Studies are testing specific bacterial strains and fecal microbiota transplant to see if changing gut bacteria composition can reduce IBS symptoms. Some trials focus on people whose IBS started after an infection.
Bile acid modulators
Drugs that control bile acid levels in the gut are being tested for IBS with diarrhea. Some people with IBS appear to have problems absorbing bile acids, which can trigger symptoms.
Gut-brain axis treatments
Trials are testing how medications and behavioral therapies that affect brain-gut signaling can reduce pain and other symptoms. This includes low-dose neuromodulators and specialized cognitive behavioral therapy.
What to know before you search
Eligibility typically depends on IBS subtype (diarrhea-predominant, constipation-predominant, or mixed), symptom severity, duration of symptoms, and whether other bowel diseases have been ruled out.
What types of trials are currently open
- Treatment trials — Testing new medications that target gut motility, secretion, or pain signaling to reduce abdominal pain, bloating, and irregular bowel movements.
- Microbiome trials — Testing probiotics, specific bacterial strains, or fecal microbiota transplant to see if changing gut bacteria helps symptoms.
- Diet trials — Studying low-FODMAP diets, elimination diets, or specific dietary interventions to identify which foods trigger symptoms and how diet changes compare to medications.
- Behavioral trials — Testing gut-directed hypnotherapy, cognitive behavioral therapy, and other psychological approaches that address the brain-gut connection in IBS.
- Diagnostic studies — Following people with IBS to identify biomarkers, understand subtypes, and learn what predicts treatment response.
Recently added Irritable Bowel Syndrome trials
The Role That Food and Bacteria Play in Generating Abdominal Pain
Irritable Bowel Syndrom (IBS) affects up to five percent of Canadians and has proven difficult to treat. Our research will explore how a type of dietary carbohydrate, called FODMAPS, contributes to chronic abdominal pain in irritable bowel syndrome (IBS). FODMAPs, are poorly digested carbohydrates and removing FODMAPs from the diet relieves abdominal pain in approximately half of IBS patients. Unfortunately, FODMAPs are contained in many foods, which makes it challenging for patients to remain on a low FODMAP diet for extended periods. Our proposed research will identify which subtypes of FODMAPs are most responsible for increasing pain and will tease apart whether the pain-causing effects of FODMAPs rely on the gut microbiota or not. To identify which specific type of FODMAP causes pain, IBS patients will adopt a low FODMAP diet and then individual FODMAP subtypes will be added back to their diet while monitoring changes to their pain. Stool samples will be collected from the participants to determine whether the composition of the gut microbiota or the chemicals that it produces are changed when symptoms are improved or exacerbated by manipulating FODMAP availability. In parallel studies, the microbiota of each IBS patient will be grown in specialized conditions to mimic the environment of the gut. These patient microbial communities will be exposed to the same FODMAP manipulations as the patients themselves experience. This will allow us to test whether the changes in gut microbiota composition and the chemicals produced that occur in IBS patients in response to FODMAP manipulations also occur when only the microbiota is exposed to these manipulations. Together, these studies will aim to optimize a dietary therapy for a common chronic pain condition and will provide novel insights into how diet affects the chemicals the gut microbiota produces that contribute to abdominal pain.
Effects of the Multispecies Probiotic Ecologic Barrier in IBS Patients With Upper GI Symptoms and Anxiety, Depression, or Stress
The aim of this clinical trial is to find out whether Ecologic Barrier is effective in supporting the treatment of irritable bowel syndrome (IBS) in adults. The main questions that this trial aims to answer are: * Does Ecologic Barrier help improve IBS severity when added to standard IBS treatment? * Does Ecologic Barrier help improve symptoms of anxiety, depression, and stress in patients with IBS? * Does Ecologic Barrier help improve upper gastrointestinal symptoms when added to standard IBS treatment? * What adverse events may occur when using Ecologic Barrier? The researchers will compare a group receiving standard symptom-based treatment with another group receiving standard treatment plus Ecologic Barrier. Participants will: * Receive IBS treatment for 2 months, with Ecologic Barrier added during either the first month or the second month, depending on random assignment. * Attend a follow-up visit after 1 month of treatment. * Take part in interviews about IBS severity, symptom improvement, adverse events, and symptoms of depression and anxiety at baseline, 2 weeks, 4 weeks, 8 weeks, and 12 weeks.
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