S1183 Symptom-Specific Effects of the Low FODMAP Diet Versus Traditional Dietary Advice in IBS: A Meta-Analysis

Introduction: Dietary strategies are foundational in managing irritable bowel syndrome (IBS), yet traditional approaches often provide incomplete relief. The low fermentable oligo-, di-, monosaccharides, and polyols (FODMAP) diet has emerged as a promising intervention. This meta-analysis evaluates its symptom-specific effectiveness compared to conventional dietary advice, focusing on global symptom severity, abdominal pain, bloating, bowel habits, and quality of life (QoL). Methods: A systematic search through January 2015 identified randomized controlled trials comparing low FODMAP diets with standard dietary modifications in adults diagnosed with IBS. Eligible studies reported outcomes using validated scales: IBS Symptom Severity Scale (IBS-SSS), Likert scale for bloating and pain, Bristol Stool Scale, and QoL indices, with a minimum follow-up of 4 weeks. Pooled standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated using a random-effects model. Results: Six trials (n = 291) were included. The low FODMAP diet was associated with a significant reduction in overall IBS symptoms (SMD -0.58; 95% CI: -0.99 to -0.18; I² = 75%). Symptom-specific improvements were observed in abdominal pain (SMD -0.28; 95% CI: -0.50 to -0.06; I² = 11%) and bloating (SMD -0.39; 95% CI: -0.60 to -0.18; I² = 0%). No significant differences were found in bowel habit normalization (SMD -0.24; 95% CI: -0.52 to 0.05; I² = 0%) or QoL (SMD -0.21; 95% CI: -0.56 to 0.14; I² = 48%). Conclusion: The low FODMAP diet demonstrated clear benefits in reducing global IBS symptom severity, abdominal pain, and bloating compared to traditional dietary advice. However, its influence on bowel patterns and QoL remains uncertain. These findings highlight the clinical value of the low FODMAP approach in symptom-targeted IBS management and reinforce the need for longer-term trials addressing durability and patient-centered outcomes.