Disease concept and definition of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a disease entity characterized by recurrent abdominal pain or discomfort associated with altered bowel movement, in which no obvious pathogenetic lesion is identified to explain the symptoms. Postulated pathogenesis for IBS are; motility disorder, visceral sensation abnormalities, complex relationship between brain and gut, relationship to personality, and post-infectious abnormalities in the colonic mucosa. Though many possibilities are presented, diagnostic criteria for IBS are entirely based on the subjective symptoms of the patients. Stress or psychological distress seem to play some roles in the pathogenesis, any of the diagnostic criteria for IBS do not include such aspects. Manning's criteria seem to be the first one to mention the diagnostic criteria. Rome consensus (1988) provoked the attention to IBS among the investigators, with followers like Rome II (1999), and BMW(2000) in Japan. Recently, Rome III criteria was published, which is more clinical oriented.