Angiodysplasia of the colon Health Article

Definition

Angiodysplasia of the colon is enlarged and fragile blood vessels in the colon that result in occasional loss of blood from the gastrointestinal (GI) tract.

Alternative Names

Vascular ectasia of the colon; Colonic arteriovenous malformation; Colonic angiomas

Causes, incidence, and risk factors

Angiodysplasia of the colon is mostly related to the aging and degeneration of the blood vessels. It usually occurs in older adults.

There are several theories about the cause. The most likely cause is that normal spasms of the colon lead to enlargement of blood vessels in the area. This swelling becomes so severe that a small direct passageway develops between a very small artery and vein. This is called an arteriovenous fistula. It is in this area of the colon wall that the patient is at risk for bleeding.

Angiodysplasia of the colon is very rarely related to other diseases of the blood vessels, including Osler-Weber-Rendu syndrome. It is not related to cancer, and is different than diverticulosis, another very common cause of intestinal bleeding in older adults.

Symptoms

The symptoms vary. Often, in elderly patients, the symptoms are weakness, fatigue, and shortness of breath due to anemia. There may not be any signs of bleeding directly from the colon. Others may have occasional mild or severe bleeding episodes with bright red blood coming from the rectum.

Some patients may have dark or black, tarry stools. There is no pain associated with angiodysplasia.

Signs and tests

Tests that may be done to diagnose this condition include:

• Angiography (only useful if there is active bleeding into the colon)
• Complete blood count (CBC) to check for anemia
• Colonoscopy
• Stool guaiac test (a positive test result suggests bleeding from the colon)