Spectrum of chronic dyspepsia in the presence of the irritable bowel syndrome.

The irritable bowel syndrome is characterized by the presence of abdominal pain associated with disturbed defecation; certain symptoms are able to discriminate the irritable bowel syndrome from organic disease. Functional dyspepsia is also common in patients with symptoms otherwise compatible with the irritable bowel syndrome. Approximately one-third of patients with functional dyspepsia have symptoms thought to be of colonic origin. Despite this, functional dyspepsia can be distinguished from the irritable bowel syndrome on the basis of symptom criteria. A generalized motility disturbance may explain the presence of dyspepsia in patients with the irritable bowel syndrome. Whether a specific type of dyspepsia occurs in this syndrome is not established.