Food intolerance in functional bowel disorders

Food-related symptoms are commonly described by patients with functional bowel disorders, but dietary change as an evidence-based therapy has not been part of routine management strategies. This reviews aims to discuss strategies commonly applied.

Published literature was reviewed.

Traditional approaches involve elimination diets followed by placebo-controlled reintroduction of specific foods, which is tedious at best and not applied in routine practice. Pathogenically-based approaches include determining what food components are inducing food hypersensitivity responses using specific biomarkers, but this is probably applicable to a small proportion of patients only and has met with only limited success. Food bioactive chemicals, such as salicylates, have been targeted, but there is a paucity of quality evidence for or against this approach. In contrast, targeting poorly absorbed dietary components that might induce luminal distension via osmotic effects and rapid fermentation (FODMAPs) has been successful and the efficacy of the dietitian-delivered low FODMAP diet is now supported by high quality evidence. Improvement of all symptoms of FBD in three out of four patients has been achieved. The diet may potentially improve stool frequency in patients with an ileal pouch or a high output ileostomy, or functional symptoms in patients with inflammatory bowel disease. FODMAPs in enteral formulas may also be responsible for diarrhoea induced by enteral nutrition.

Dietary restriction of FODMAPs is an effective therapy in the majority of patients with functional bowel symptoms and, provided dietitians are trained in the technique, should be first line therapy.