The role of nutrition in the treatment of irritable bowel syndrome

Background
The prevalence of functional bowel disorders is on the rise worldwide. Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized mainly by abdominal cramps, flatulence, and abnormal bowel movements. Due to the lack of specific biomarkers and of a specific diagnostic test, IBS is diagnosed according to the Rome IV clinical criteria. The current holistic approach recommends dietary management as the initial therapy for IBS patients with mild and moderate symptoms.

Objectives
This review examines the studies on the effect of various types of diets on IBS as well as on the primary dietary therapy in IBS patients.

Material and methods
A literature review of published studies was conducted by searching the Medline-PubMed database using the MeSH (Medical Subject Headings) descriptor and the following keyword combinations: “irritable bowel syndrome” and “treatment” (n = 11 articles), “irritable bowel syndrome” and “diet or nutrition” (n = 26 articles), “irritable bowel syndrome” (n = 9 articles), and “gluten”, “irritable bowel syndrome” and “lactose” (n = 4 articles).

Results
Contradictory results were found in many studies regarding several diets such as diet excluding gas-producing foods, diet low in lactose, gluten-free diet, diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) and the role of fiber, alcohol, caffeine, and natural remedies and their applications in different IBS subtypes.

Conclusions
Short-term restriction of FODMAP may be the most effective dietary intervention for reducing IBS symptoms compared to other types of diet.