Vascular ectasia of the colon; Colonic arteriovenous malformation
Angiodysplasia of the colon is swollen, fragile blood vessels in the colon that occasionally result in blood loss from the gastrointestinal (GI) tract.
Angiodysplasia of the colon is mostly related to the aging and degeneration of the blood vessels. It usually occurs in older adults. It is almost always seen on the right side of the colon.
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, a more common cause of intestinal bleeding in older adults.
Hauser S. Vascular diseases of the gastrointestinal tract. In: Goldman L, Ausiello D. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 146.
Brandt LJ, Landis CS. Vascular lesions of the gastrointestinal tract. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 36.
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