Hematochezia is the passage of bloody stools from the rectum.Stedman's Dictionary. URL: http://www.emedicine.com/asp/dictionary.asp?keyword=hematochezia. Accessed on: June 10, 2006. It is commonly associated with lower gastrointestinal bleeding.

The most common causes are hemorrhoids and diverticulosis (which are relatively benign); however, it can also be caused by colorectal cancer, which is frequently fatal.

Hematochezia can be due to upper gastrointestinal bleeding. However, as the blood from upper GI bleeding is usually chemically modified by action of acid and enzymes, it presents more commonly as melena. Hematochezia from an upper GI source is an omninous sign, as it suggests a very brisk bleed which is life threatening.

See also

• Blood in stool

References