The spectrum of colonic diverticular disease includes asymptomatic diverticulosis, acute and chronic diverticulitis, and diverticular hemorrhage. Most often discovered incidentally on endoscopy or contrast radiography, asymptomatic diverticulosis is best treated by patient education, which focuses on increasing dietary fiber intake. Acute diverticulitis can be managed on either an inpatient or outpatient basis, depending on the severity of the symptoms, with bowel rest and broad spectrum-antibiotics. Surgery is indicated for complications of the acute inflammatory process, including failure of medical treatment, gross perforation, and abscess formation that cannot be resolved by percutaneous drainage. Manifestations of chronic diverticulitis (fistula formation, stricture, and obstruction) are most often treated surgically. Diverticular hemorrhage is most often massive and self-limited. It requires aggressive resuscitation and a thorough evaluation aimed at localizing the bleeding site. Patients whose bleeding stops spontaneously are treated expectantly. Actively bleeding patients whose bleeding site is successfully localized can be initially treated by selective infusion of vasoconstrictive agents. Recurrent or persistent bleeding requires surgical resection.