In rare cases, an infected or inflamed pouch may rupture, spilling intestinal waste into your abdomen and leading to peritonitis — an inflammation of the lining of your abdominal cavity (peritoneum). Peritonitis is a medical emergency and requires immediate care.

Other complications of diverticulitis may include a blockage in your colon or small intestine, an abscess or a fistula. A fistula is an abnormal passageway that occurs between different parts of your intestine, your intestine and your bladder or vagina, or your intestine and abdominal wall. Sometimes fistulas themselves become infected — a condition that can be life-threatening if left untreated.

Although there is no evidence that diverticular disease increases your risk of colon or rectal cancer, it can make cancer more difficult to diagnose. Because of this, your doctor may recommend a colonoscopy after you've recovered from a bout of diverticulitis along with more frequent cancer screening tests. A colonoscopy is a test that allows your doctor to examine your entire colon and rectum for abnormalities using a long, flexible tube with a tiny video camera at the tip (colonoscope).