Irritable bowel syndrome (IBS) is a functional gut disorder causing abdominal pain, bloating, and altered bowel habits — either diarrhea, constipation, or alternating between them — without any structural damage. It affects around 10% of people globally and is one of the most common reasons for gastroenterology visits.
What's actually going on in research
The gut microbiome is a central focus: rifaximin (an antibiotic that acts in the gut without absorbing into the blood) and fecal microbiota transplant are being tested in IBS-D. Drugs targeting gut-brain signaling pathways — including serotonin receptors, opioid receptors, and mast cell stabilizers — are in development. Digital CBT programs specifically targeting the gut-brain axis in IBS have shown effectiveness comparable to medication in trials.
Microbiome therapies
Rifaximin reshapes the gut microbiome in IBS-diarrhea, and fecal microbiota transplant trials are investigating whether donor stool can normalize gut bacteria and improve symptoms durably.
Gut-brain axis drugs
Mast cell stabilizers, serotonin receptor modulators, and drugs targeting intestinal permeability are being tested to address the visceral hypersensitivity driving IBS pain.
Digital gut-brain therapy
App-delivered and therapist-guided gut-directed hypnotherapy and CBT programs show strong improvements in IBS pain and quality of life and are being validated in sham-controlled trials.
What to know before you search
Eligibility requires IBS diagnosis by Rome IV criteria with specified subtype (IBS-D, IBS-C, or IBS-M), symptom severity, and exclusion of inflammatory bowel disease.
What types of trials are currently open
- Drug trials — Testing new IBS medications targeting gut motility, visceral sensitivity, microbiome, or intestinal permeability.
- Microbiome trials — Evaluating rifaximin, probiotics, and fecal microbiota transplant for IBS subtypes.
- Dietary trials — Testing low-FODMAP diet, gluten-free diet, and fiber supplements in different IBS subtypes.
- Behavioral therapy trials — Comparing gut-directed hypnotherapy, CBT, and mindfulness for IBS symptoms.
- Device and technology trials — Testing digital therapeutics, gut monitoring wearables, and biofeedback for IBS management.
Recently added Irritable Bowel Syndrome trials
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.
Anxiety and Depression in IBS: A Brain-Gut Axis Study
This study aims to understand how the gut and the brain communicate in people with Irritable Bowel Syndrome (IBS) who also experience anxiety and depression. We want to see if changes in gut bacteria are linked to changes in brain function, and to find potential markers that could help in diagnosis or future treatments. We are looking for two groups of volunteers aged 18 to 60 years: 1) 100 patients diagnosed with IBS who also have symptoms of anxiety or depression, and 2) 100 healthy volunteers for comparison. All participants must be right-handed. Participants in this observational study will not receive any new drug or treatment. Instead, they will be asked to: Complete questionnaires about their bowel symptoms, anxiety, depression, sleep, and thinking skills. Provide a stool sample (about 5 grams) and a blood sample (about 5 ml). Undergo a brain scan using a 7 Tesla MRI machine, which will take about 45-50 minutes. They will need to lie still during the scan. Some IBS patients may be invited for a follow-up visit after 3 months to repeat the questionnaires and sample collection. There are minimal risks involved. The MRI scan is non-radioactive and considered very safe, but some people may feel uncomfortable or claustrophobic inside the machine. Giving blood may cause brief pain, bruising, or, very rarely, infection. Your privacy is protected. All personal information and data will be coded and kept confidential, and will only be used for this research. The main benefit to participants is receiving a detailed health assessment, including advanced brain imaging and analysis of gut bacteria, at no cost. There is no direct therapeutic benefit from participating, but the knowledge gained may help improve the understanding and future care of IBS.
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