Low FODMAP Diet Most Likely to Improve Symptoms in Patients With Irritable Bowel Syndrome

Clinical Question

Is a low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet effective for the treatment of irritable bowel syndrome (IBS)?

Bottom Line

A network meta-analysis of the literature concluded that a low FODMAP diet is most likely to be effective for patients with IBS compared with other diets. A low FODMAP diet removes offending foods from the diet for four to six weeks followed by a gradual and systematic reintroduction of foods to identify those that the patient can tolerate. (Level of Evidence = 1a−)

Synopsis

The network meta-analysis included 13 studies and 944 patients with IBS. The studies were small (i.e., 30 to 110 patients), used the Rome III criteria to identify eligible patients, and compared a low FODMAP diet with usual diet, dietitian advice, or the diet recommended by the British Dietetic Association. Nine trials were at low risk of bias across all domains other than double masking. Most studies enrolled patients who had IBS with constipation and IBS with diarrhea. The network meta-analysis combined direct and indirect comparisons and concluded that the low FODMAP diet was most likely to reduce pain, bloating, and distention; improve bowel symptoms; and improve global IBS symptoms. The low FODMAP diet was superior to the patient's usual diet and the British Dietetic Association's recommended diet.

Study design: Meta-analysis (randomized controlled trials)

Funding source: Self-funded or unfunded

Setting: Outpatient (any)

Reference: Black CJ, Staudacher HM, Ford AC. Efficacy of a low FODMAP diet in irritable bowel syndrome: systematic review and network meta-analysis. Gut. 2022;71(6):1117-1126.

Editor's Note: Dr. Ebell is deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell.