Effect of a Low FODMAP Diet in IBS and Functional Constipation with Bloating: a Randomized Double… (NCT06871748) | Clinical Trial Compass
Not Yet RecruitingNot Applicable
Effect of a Low FODMAP Diet in IBS and Functional Constipation with Bloating: a Randomized Double-Blind Trial
34 participantsStarted 2025-03-15
Plain-language summary
This clinical study aims to evaluate the effects of a low FODMAP diet compared to a high FODMAP diet in patients with Irritable Bowel Syndrome (IBS) and Functional Constipation (FC) with predominant bloating. The study is a randomized, double-blind, controlled trial designed to assess whether a diet low in fermentable carbohydrates can improve bloating symptoms, gut microbiota composition, intestinal gas production, and metabolic outputs.
Patients meeting the Rome IV criteria for IBS or FC with persistent bloating will be enrolled and randomly assigned to receive either a low or high FODMAP diet for two weeks. Meals will be standardized to control FODMAPs composition, ensuring that FODMAP content is the primary variable.
The primary endpoint is the proportion of participants with a ≥30% reduction in bloating severity, measured using the Visual Analog Scale (VAS). Secondary outcomes include changes in global IBS symptoms, abdominal pain, bowel movements, stool consistency, microbiota diversity, hydrogen/methane gas production, and metabolomic profiles.
This study will contribute to the growing body of evidence supporting dietary management in disorders of gut-brain interaction (DGBI), particularly in bloating-predominant IBS and FC, and will provide insights into the mechanisms linking diet, gut microbiota, and symptom improvement.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Age ≥18 years
* Diagnosed with Irritable Bowel Syndrome (IBS) or Functional Constipation (FC) based on Rome IV criteria
* Persistent bloating affecting daily life, with a bloating VAS score ≥4
* Stable bowel habits with Bristol Stool Form Scale (BSFS) type 3-5
* History of prior treatment with antispasmodics and/or prokinetics (allowed if dose remains stable)
* Able to comply with dietary intervention and study procedures
Exclusion Criteria:
* Prior gastrointestinal surgery (except appendectomy or cholecystectomy)
* Use of antibiotics, proton pump inhibitors (PPIs), probiotics, NSAIDs, lactulose, or metformin within the past 4 weeks
* Presence of systemic diseases affecting gut microbiota (e.g., liver cirrhosis, uncontrolled diabetes, end-stage renal disease, obesity, cancer, psychiatric disorders)
* Inability to consume study meals or follow dietary restrictions
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Change in Bloating Severity (VAS)
Timeframe: Baseline to 2 weeks (End of Intervention)