Angiodysplasia of the colon

Definition

Angiodysplasia of the colon is a condition of stretched and fragile blood vessels in the colon that results in occasional loss of blood from the gastrointestinal (GI) tract. The condition is mostly related to the aging and degeneration of the blood vessels, and occurs in older adults.

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

Alternative Names

Causes

There are several theories about the cause of angiodysplasia of the colon. The most likely is that normal contractions of the colon result in dilation (stretching) of colonic veins, venules, and capillaries. The dilation becomes so severe that a small direct passageway develops between the artery and vein (arteriovenous fistula). It is in this area of the colon wall that the patient is at risk for bleeding.

Angiodysplasia of the colon has been seen in about 3% of "nonbleeding persons" and in about 5% of patients evaluated for blood in the stool, anemia, or hemorrhage. Men and women are equally at risk for developing angiodysplasia of the colon. Most patients are older than 50 years.