Irritable bowel syndrome: disease definition and symptom description.

According to the Rome criteria, both abdominal pain and disordered defecation must be present to make a diagnosis of the irritable bowel syndrome (IBS). While established morphologic or physiologic tests are unavailable to diagnosis IBS, there are candidate biological markers; the evidence overall supports the concept that IBS is a true disease of gut function. The Rome criteria were derived from epidemiological and clinical studies, and were developed by consensus. The clinical and epidemiological evidence supporting current IBS diagnostic criteria and their limitations are summarised in this review. Symptom based subgroups of IBS may be identifiable based on symptom predominance although this remains controversial; a classification is proposed here. The Rome criteria represent a starting point; well designed studies are now needed to refine and if necessary revise current criteria.