Is a Simplified, Less Restrictive Low FODMAP Diet Possible? Results From a Double-Blind, Pilot Randomized Controlled Trial

A low fermentable oligo-, mono-, di-saccharides, and polyols (FODMAPs) diet (LFD) is the most evidence-based dietary therapy for patients with irritable bowel syndrome (IBS).¹ However, the current step-down approach to the LFD has significant limitations including being costly, complex, time-consuming, and associated with reduced dietary intake of some micronutrients.^2-4 Recently, a step-up approach has been proposed that restricts only a limited number of FODMAPs initially, evaluating symptom response and restricting additional FODMAPs only if necessary.^2,5,6 In a double-blind trial, fructans and galacto-oligosaccharides were found to be the most likely FODMAP subgroups to trigger IBS symptoms.⁷ To date, no study has compared the efficacy of a traditional LFD restriction phase with a more targeted or simplified restriction phase. In a double-blind, pilot-feasibility randomized controlled trial, we compared the efficacy of a 4-week FODMAP-simple restriction phase (eliminating solely fructans and galactooligosaccharides) and a traditional LFD restriction phase in patients with IBS with diarrhea (IBS-D) (ClinicalTrials.gov registration number NCT05831306).