Diverticular disease refers to symptomatic and asymptomatic disease with an underlying pathology of colonic diverticula. Predisposing factors for the formation of diverticula include a low-fiber diet and physical inactivity. Approximately 85 percent of patients with diverticula are believed to remain asymptomatic. Symptomatic disease without inflammation is a diagnosis of exclusion requiring colonoscopy because imaging studies cannot discern the significance of diverticula. Fiber supplementation may prevent progression to symptomatic disease or improve symptoms in patients without inflammation. Computed tomography is recommended for diagnosis when inflammation is present. Antibiotic therapy aimed at anaerobes and gram-negative rods is first-line treatment for diverticulitis. Whether treatment is administered on an inpatient or outpatient basis is determined by the clinical status of the patient and his or her ability to tolerate oral intake. Surgical consultation is indicated for disease that does not respond to medical management or for repeated attacks that may be less likely to respond to medical therapy and have a higher mortality rate. Prompt surgical consultation also should be obtained when there is evidence of abscess formation, fistula formation, obstruction, or free perforation.