The presence of diverticula (see DIVERTICULUM) or sacs in the large intestine. Such diverticula are not uncommon over the age of 40, increasing with age until over 70 years; they may be present in one-third to one-half of the population. Diverticula mostly occur in the lower part of the COLON, and are predominantly due to muscular hyperactivity of the bowel forcing the lining of the bowel through weak points in the bowel wall, just as the inner tube of a pneumatic tyre bulges through a defective tyre. There is increasing evidence that the low-residue diet of western civilisation is a contributory cause. The condition may or may not produce symptoms. If it does, these consist of disturbance of the normal bowel function and pain in the left side in the lower abdomen. If diverticulosis is causing symptoms, treatment consists of a high-residue diet (see CONSTIPATION) and an AGAR or METHYLCELLULOSE preparation.
Summary Article: Diverticulosis
from Black's Medical Dictionary, 43rd Edition