Dietary Treatment of the Irritable Bowel Syndrome.

Most patients with functional gastrointestinal disorders report that food ingestion appears to exacerbate their symptoms and consequently conclude that they have some form of gastrointestinal food allergy or intolerance. Dietary management of functional gastrointestinal conditions is an attractive therapeutic option for the patient and physician alike because it is safe and economical and empowers the patient to help themselves. However, in practice, dietary manipulation frequently yields rather disappointing results. Exclusion diets can be helpful, but are labor intensive and occasionally can be very restrictive. Laboratory testing for immunoglobulin E food antibodies usually is not helpful, except in a small subgroup of patients with diarrhea, predominant irritable bowel syndrome (IBS), and atopy. There is some preliminary evidence to suggest that elimination diets based on immunoglobulin G food antibody testing may possibly have therapeutic potential in IBS, but this requires confirmation.