S401 Efficacy of the Low FODMAP Diet in the Management of Irritable Bowel Syndrome: A Systematic Review of Clinical Trials

Introduction: Irritable bowel syndrome (IBS) symptoms are often triggered by what you eat. Evidence shows that a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet can help improve symptoms of IBS, mainly in those with bloating and diarrhea. Limiting FODMAPs stops the body from producing much gas and helps the gut hold less water, which eases IBS problems for several patients. Clinical research suggests the low-FODMAP diet greatly relieves abdominal discomfort, bloating, and stool consistency in IBS. Methods: A thorough review was done to check how effective a low-FODMAP diet is for people with irritable bowel syndrome. Between 2000 and 2025, searches were made on PubMed, Google Scholar, Cochrane Library, and Scopus etc for randomized trials and observational studies studying low-FODMAP diets versus typical diets or other meals. Global symptom relief, individual symptoms, and quality of life were all included in the dataset. The quality of studies was decent (blinding was a problem). Results: We reviewed 24 studies (including 8 randomized controlled trials [RCT]) involving ∼1,700 IBS patients. Most showed that the low-FODMAP diet led to greater symptom relief than standard IBS diets. Between 50%–75% of patients on a low-FODMAP diet experienced significant improvement, compared to 33%–66% on other diets. One RCT reported 57% improvement with the low-FODMAP diet vs 20% in the control group. The diet consistently reduced abdominal pain, bloating, and improved quality of life. However, long-term restriction may reduce beneficial gut bacteria like Bifidobacteria, so supervised reintroduction is essential. No serious adverse effects were noted. Overall, evidence quality was moderate, but findings across diverse populations support its benefit. Conclusion: The low-FODMAP diet is highly effective for managing IBS, particularly symptoms like diarrhea and bloating, and has the strongest evidence among dietary approaches. It reduces pain, bloating, and digestive issues, often decreasing the need for medication. However, long-term restriction may harm gut health, so reintroduction under a dietitian’s guidance is recommended. Overall, it’s considered the first-line dietary therapy for IBS, with attention to nutritional balance and gut microbiota.