The Inferior mesenteric artery is a branch of the abdominal aorta. It is the third of the three arteries that supply the gastrointestinal tract:
The inferior mesenteric artery supplies circulation for the entire
large intestine including the
colon and
rectum.
This artery is important to the correct functioning of the human digestive system. Stenosis (narrowing) of this artery decreases blood flow to the large intestine, and can cause abdominal angina or rectal bleeding. Chronic narrowing can result in diarrhea or constipation as well as dysmotility disorders. Blockage of the artery causes mesenteric and intestinal ischemia and will result in necrosis of the large intestine unless surgically treated or otherwise reversed immediately. Loss of the colon is not fatal, however, and if the colon has undergone irreversible damage, it can be removed and replaced with a colostomy.
References:
www.mythos.com/webmd/Content.aspx?P=CIRCA1&E=41