Role of food hypersensitivity in irritable bowel syndrome.

A significant proportion of IBS patients attribute their symptoms to adverse food reactions. Dietary elimination and re-challenge studies support the role of diet in the pathogenesis of IBS. The aetiopathogenesis of IBS is thought to be multifactorial involving an interaction between diet, infection, antibiotics and psychosocial factors. Serum IgE and IgG4 antibodies are elevated in food hypersensitivity induced atopic conditions and a similar mechanism has been postulated in IBS. Increased number of mast cells is present in the ileocaecal region of IBS patients. Once sensitized, they are capable of inducing secretory and sensorimotor abnormalities of the gut. The management of IBS is usually aimed at controlling symptoms, however, evaluation of food hypersensitivity may provide a useful adjunct in those with severe symptoms or a clear history of adverse food reaction. There are no well-established tests available but skin prick tests and food specific serum IgG4 and IgE antibodies may help in identifying the offending foods. Other options, which may be explored in individual cases, include sequential dietary exclusion, use of hypoallergenic diets, disodium cromoglycate and novel techniques such as colonoscopic allergen provocation test. Pathophysiology of hypersensitivity induced IBS has been discussed in the light of current data and a management algorithm has been proposed for managing food hypersensitivity in IBS.