Diverticulitis occurs when the pouches become infected or inflamed. This condition usually produces localized abdominal pain, tenderness to touch and fever. A person with diverticulitis may also experience nausea, vomiting, shaking, chills or constipation. Your doctor may order a CT scan to confirm a diagnosis of diverticulitis. Minor cases of infection are usually treated with oral antibiotics and do not require admission to the hospital. If left untreated, diverticulitis may lead to a collection of pus (called an abscess) outside the colon wall or a generalized infection in the lining of the abdominal cavity, a condition referred to as peritonitis. Usually a CT scan is required to diagnose an abscess, and treatment usually requires a hospital stay, antibiotics administered through a vein and possibly drainage of the abscess. Repeated attacks of diverticulitis may require surgery to remove the affected portion of the colon. Bleeding in the colon may occur from a diverticulum and is called diverticular bleeding. This is the most common cause of major colonic bleeding in patients over 40 years old and is usually noticed as passage of red or maroon blood through the rectum. Most diverticular bleeding stops on its own; however, if it does not, a colonoscopy may be required for evaluation. If bleeding is severe or persists, a hospital stay is usually required to administer intravenous fluids or possibly blood transfusions. In addition, a colonoscopy may be required to determine the cause of bleeding and to treat the bleeding. Occasionally, surgery or other procedures may be necessary to stop bleeding that cannot be stopped by other methods. Intestinal blockage may occur in the colon from repeated attacks of diverticulitis. In this case, surgery may be necessary to remove the involved area of the colon.