Types and Outcomes of Dietary Interventions in IBS: A Scoping Review

Irritable bowel syndrome (IBS) is primarily treated via dietary modifications. Several diets have been shown to improve symptoms with similar efficacy. Other aspects of IBS, such as insufficient nutrient intake and being overweight, should also be considered when planning treatment options. The present scoping review aimed to identify various diets investigated in IBS-related clinical trials and to map the measured outcomes.

We performed a systematic search of three databases: PubMed, Embase, and CINAHL Ultimate. Our search was limited to papers published between January 2000 and February 2026, and included human studies published as peer-reviewed original articles in English that described dietary interventions in adult patients (≥18 years) with IBS.

The titles and abstracts of 1261 studies were screened; 1147 studies were excluded; and 114 full-text articles were assessed for eligibility. Excluding articles outside the scope of our research resulted in a total of 71 included articles from 57 unique clinical trials. The most common interventions were low fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) (n = 43), traditional dietary advice (n = 13), and gluten-free diets (n = 11). The most common primary outcomes were the effect on IBS symptoms (n = 48), efficacy in terms of improving quality of life (n = 10), psychological well-being (n = 7), nutrient intake (n = 7), and adherence/applicability/feasibility to the diet (n = 7).

In conclusion, the most studied dietary intervention in IBS was low FODMAP, and an effect on GI symptoms was the most common outcome. Considering other conditions associated with IBS, the effects on anthropometric, endocrine, metabolic, and nutritional parameters should also be evaluated.