Is Ischemic Colitis Ischemic?

Ischemic colitis appears to be a collection of diseases rather than a single entity. On the one hand, there is the colitis that truly appears to be caused by a lack of blood flow and, on the other hand, there is the disease that is called ischemic for lack of a better diagnosis-the colitis that is more idiopathic than ischemic. Four widely held tenets of ischemic colitis are wrong: 1) the colon is not particularly sensitive to ischemia; 2) ischemic colitis is rarely preceded by a period of global hypoperfusion; 3) the watershed areas are not disproportionately affected; and 4) colonoscopy with biopsy is not specific for the disease. The cause of ischemic colitis is unknown. Therefore it is, until proven otherwise, acute idiopathic colitis.