What does melena indicate?

Melena refers to the passage of black, tarry stools that result from the digestion of blood, typically originating from an upper gastrointestinal source such as the stomach or duodenum. The dark coloration and tarry consistency of these stools are due to the breakdown of hemoglobin, which occurs during the long transit time through the intestines. This condition is often a sign of bleeding in the upper digestive tract and warrants immediate medical evaluation to determine the cause. Understanding that melena is specifically associated with this characteristic type of stool is crucial for recognizing potential serious health issues.