Diet and Irritable Bowel Syndrome
The prevalence of irritable bowel syndrome (IBS) has increased over the last 50 years in countries where a Western style diet has been prominent or introduced. Compared with previous centuries, such diets generally contain less fiber and complex starch and more refined sugars and chemical additives. There is a sense that more food allergies, especially to recent additives, may be expressed. In addition, meals tend to be eaten on a more irregular or hurried basis. Despite these changes, relatively few carefully controlled studies on the effect of diet or dietary components (with the exception of lactose) on symptom generation have been carried out in IBS patients. Part of this paucity of information results from confusion between food intolerance, food allergy, the effect of intestinal bacterial flora on ingested food, and food 'sensitivity' that is not related to physiological intolerance or to true allergy. This review will briefly consider recent findings in each of these areas.