colonic angiodysplasia

Last reviewed 01/2018

Colonic angiodysplasia is a common cause of acute or chronic rectal bleeding and iron deficiency anaemia.

Angiodysplasias are tiny - 1-5 mm in diameter - hamartomatous capillary lesions in the colonic wall which produce bleeding out of proportion to their size. They are believed to be acquired, possibly as a result of tension on the veins where they pass through the muscularis.


  • subtraction mesenteric arteriography may demonstrate bleeding if rapid
  • colonscopy: may visualise lesion


  • electrical coagulation via the colonoscope
  • resection of segment of colon if the above is unsuccessful