A Diet Low in Fermentable Oligo-, Di-, and Monosaccharides and Polyols Improves Quality of Life and Reduces Activity Impairment in Patients with Irritable Bowel Syndrome and Diarrhea

BACKGROUND & AIMS: We investigated the effects of a diet low in fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) vs traditional dietary recommendations on health-related quality of life (QOL), anxiety and depression, work productivity, and sleep quality in patients with irritable bowel syndrome and diarrhea (IBS-D). METHODS: We conducted a prospective, single-center, single-blind trial of 92 adult patients with IBS-D (65 women; median age, 42.6 years) randomly assigned to groups placed on a diet low in FODMAPs or a modified diet recommended by the National Institute for Health and Care Excellence (mNICE) for 4 weeks. IBS-associated QOL (IBS-QOL), psychosocial distress (based on the Hospital Anxiety and Depression Scale), work productivity (based on the Work Productivity and Activity Impairment), and sleep quality were assessed before and after diet periods. RESULTS: Eighty-four patients completed the study (45 in the low-FODMAP group and 39 in the mNICE group). At 4 weeks, patients on the diet low in FODMAPs had a larger mean increase in IBS-QOL score than did patients on the mNICE diet (15.0 vs 5.0; 95% CI, -17.4 to -4.3). A significantly higher proportion of patients in the low-FODMAP diet group had a meaningful clinical response, based on IBS-QOL score, than in the mNICE group (52% vs 21%; 95% CI, -0.52 to -0.08). Anxiety scores decreased in the low-FODMAP diet group compared with the mNICE group (95% CI, 0.46-2.80). Activity impairment was significantly reduced with the low-FODMAP diet (-22.89) compared with the mNICE diet (-9.44; 95% CI, 2.72-24.20). CONCLUSIONS: In a randomized, controlled trial, a diet low in FODMAPs led to significantly greater improvements in health-related QOL, anxiety, and activity impairment compared with a diet based on traditional recommendations for patients with IBS-D.