Modification of the Low FODMAP Diet Is Feasible in the Treatment of Irritable Bowel Syndrome: A Randomised Crossover...

Irritable bowel syndrome (IBS) can be dietary managed by applying restrictions in the diet of fermentable oligosaccharides, disaccharides, monosaccharides and polyols-the low FODMAP diet. However, many patients have major difficulties integrating the diet into their daily lives.

We aimed to investigate if the three carbohydrate groups eliminated in the traditional low FODMAP diet are equally important in relieving gastrointestinal symptoms in IBS.

Nine patients with IBS according to the Rome IV criteria and referred to specialised diet therapy in private clinics were randomised in a crossover design to three different carbohydrate-modified diets: (A) low polyol diet, (B) low FOS + GOS diet and (C) low standard FODMAP diet for 4 weeks on each diet. Symptoms were assessed by the Birmingham IBS questionnaire and adequate relief (IBS-AR) and quality of life by the IBS Quality of Life Scale questionnaire (IBS-QOL) at baseline and after every intervention period by a dietitian with assessment of the intake by weekly contact. Nonparametric statistical methods were used.

Compared to baseline, the low polyol diet did not change the symptoms, but relief was significant on both the low FOS + GOS diet and the low FODMAP diet (p < 0.05) with no difference between these two diets. Clinically relevant symptom relief was experienced by 75% of patients on the low FOS + GOS diet and 62.5% on the low FODMAP diet, but none on the low polyol diet.

A carbohydrate-modified diet with the exclusion of fructooligosaccharides and galactooligosaccharides (low FOS + GOS diet) reduced gastrointestinal symptoms and improved quality of life equally to the standard low FODMAP diet in patients with IBS. Polyol restriction was of minor importance. The low FOS + GOS diet could be the starting diet in selected patients with IBS.

ClinicalTrials.gov identifier: NCT05618106.