Melena

In medicine, melaena or melena is the passage of black tarry motions per rectum (dark black feces). It is often caused by hemorrhage in the stomach or duodenum (upper gastrointestinal tract), for example by a peptic ulcer. The black color is caused by the iron in hemoglobin that is oxidized during its passage through the ileum. An upper endoscopy is usually performed to diagnose the cause.