Low-FODMAP Diet for Gastrointestinal Symptoms in Endometriosis: A Systematic Review.

Background/Objectives: Gastrointestinal (GI) symptoms, including abdominal pain, bloating, altered stool pattern, dyschezia, and nausea, are frequent in women with endometriosis and may persist despite conventional gynecological treatment. The low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (low-FODMAP) diet is an established dietary intervention for irritable bowel syndrome. Its endometriosis-specific evidence base remains limited. This systematic review evaluated clinical evidence on the low-FODMAP diet or structured FODMAP restriction for GI symptoms in women with endometriosis. Methods: This systematic review was prospectively registered in PROSPERO (CRD420261388786) and conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. PubMed/MEDLINE, EBSCOhost, and BASE were searched from inception to 30 April 2026. Eligible reports were clinical studies investigating low-FODMAP diet or structured FODMAP restriction in women with confirmed, clinically diagnosed, imaging-based, or medically reported endometriosis and extractable GI or related clinical outcomes. Risk of bias was assessed with design-specific tools. Due to substantial heterogeneity across studies in design, comparators, and outcome measures, a narrative synthesis was performed. Results: Five clinical reports met the inclusion criteria: one randomized controlled crossover feeding trial, two prospective non-randomized studies, one retrospective audit of prospectively collected clinic data, and one case report. The randomized trial showed greater GI response during a 28-day low-FODMAP feeding period than during a nutritionally matched control diet. Prospective studies reported improvements in selected GI symptoms, constipation, pain, and quality-of-life domains, but interpretation was limited by non-randomized allocation, attrition, and mixed or pooled diet comparisons. The retrospective audit and case report supported clinical plausibility but were hypothesis-generating. Conclusions: The five available studies, though limited in number and design, indicate that a low-FODMAP diet can reduce GI symptoms in women with endometriosis, particularly those with abdominal pain, bloating, constipation, or IBS-like symptoms. Currently, the low-FODMAP diet should be viewed as a potentially useful, dietitian-guided GI symptom intervention for selected patients. Future trials should define responder profiles, assess long-term tolerability and nutritional safety, and determine the added value of reintroduction and personalization beyond short-term restriction.