Final answer:
Melena refers to black, tarry stools, indicating upper gastrointestinal tract bleeding, often due to conditions like ulcers, tumors, or gastritis.
Step-by-step explanation:
Melena is a medical term that refers to the black, tarry feces that are associated with gastrointestinal bleeding in the upper gastrointestinal (GI) tract, which includes the mouth, pharynx, esophagus, and stomach. The dark color of melena is due to the digestion of blood as it travels through the gastrointestinal tract, usually indicating bleeding at a point somewhere before the small intestine.
Because the GI tract is complex, running from the mouth to the anus and including various digestive organs, a number of conditions can lead to melena, such as ulcers, tumors, or gastritis.