What is diverticular bleeding?

Diverticular bleeding occurs when pouches (diverticula) that have developed in the wall of the large intestine (colon) bleed. If you have these pouches, you have a condition called diverticulosis. Diverticular bleeding causes a large amount of blood to appear in your stool.

Diverticular bleeding usually causes sudden, severe bleeding from the rectum. The blood may be dark red or bright red clots. In most cases there is no abdominal (belly) pain.

Diverticular bleeding is diagnosed by ruling out other causes of the bleeding. Your doctor will do a medical history and physical exam, along with some tests. Imaging tests such as angiography (also known as arteriography) may be done to find the location of persistent bleeding. Colonoscopy—the inspection of the entire large intestine (colon) using a long, flexible, lighted viewing scope (colonoscope)—is thought to be one of the most useful tests for finding the source of bleeding in the lower intestines.

Your doctor might do a test called a technetium-labeled red blood cell bleeding scan to look for the source of bleeding. In this test, some blood is taken from you, and a small amount of radioactive material called technetium is added to the blood. The blood containing the technetium is then injected back into your bloodstream and traced to the source of bleeding.

Bleeding from diverticula often will stop on its own. If it doesn't, treatment may be needed to stop it and to replace lost blood, and you may need to be hospitalized. Treatment may include intravenous fluids, blood transfusions, injection of medicines, and in some cases surgery to remove the diseased part of the colon.

Your doctor will give you the information you need to care for yourself at home. Follow any instructions about eating and activity. Take prescription medicines as instructed. Ask your doctor before taking any over-the-counter medicines. And go to any follow-up appointments.