Diverticulosis coli is an anatomic abnormality of mucosal outpouchings in the colonic wall. Colonic diverticuli are often asymptomatic and the prevalence varies greatly with such factors as geographic location, dietary habits, race, and age. In the United States, the incidence has been noted to increase with age, with up to a third of the population over the age 60 being affected and over two-thirds of the population over 80 being affected.

The diagnosis of diverticulosis coli is often made incidentally in otherwise asymptomatic patients at the time of routine surveillance endoscopy. However, unless a stricture is present, most of these patients require only counseling about the need for prophylactic measures such as a fiber-rich diet, adequate fluid consumption, and the prevention of constipation. Discussion of the risk of possible infectious (up to 25% risk) or hemorrhagic complications of the disease should also be undertaken.

Clinically symptomatic diverticulosis commonly presents as acute inflammation or as lower gastrointestinal hemorrhage. While rare when compared to the frequency of diverticulosis in the population, clinically significant diverticular disease and its complications continue to tax the diagnostic and therapeutic skills of physicians. Physical findings range from diffuse slight abdominal tenderness to shock secondary to either massive hemorrhage or overwhelming sepsis. Even when clinical manifestations of diverticulosis occur, emergent surgical intervention is necessary in only a minority of patients. During such life-threatening emergencies, the physician must be prepared to resuscitate the patient quickly and proceed to surgical intervention without benefit of a definite diagnosis. These patients may have massive, or recurrent, gastrointestinal bleeding, but more commonly have generalized peritonitis that has developed after diverticular perforation.