What does "melena" refer to in medical terms?

Melena refers specifically to the passage of black, tarry stools, which result from the digestion of blood in the gastrointestinal tract. This condition typically indicates the presence of bleeding that is occurring in the upper part of the digestive system, such as the stomach or the esophagus. The black coloration is due to the breakdown of hemoglobin from the blood, undergoing chemical changes as it is exposed to digestive enzymes and bacterial action in the intestines.

Recognizing melena is essential for physicians, as it can be indicative of serious conditions, such as peptic ulcers or other sources of upper gastrointestinal bleeding. Therefore, when faced with potential gastrointestinal bleeding, the presence of melena is a significant clinical finding that requires prompt investigation and management.