What condition is identified by the presence of black, tarry stool containing digested blood?

The condition characterized by the presence of black, tarry stool that contains digested blood is known as melena. This occurs when there is bleeding in the upper gastrointestinal tract, such as from the stomach or the first part of the small intestine. The blood undergoes chemical changes as it is digested, leading to the dark, tarry appearance of the stool.

Melena is often an indication of significant gastrointestinal issues, like peptic ulcers or esophageal varices, and requires further medical evaluation to identify the source of the bleeding. Understanding this symptom is crucial for proper diagnosis and treatment, making it essential knowledge for an inpatient coder evaluating patient records related to gastrointestinal conditions.

The other conditions listed do not relate to the appearance of stool in this specific way: achalasia involves the inability of the esophagus to move food into the stomach; diverticular disease refers to pouches that form in the colon which may not necessarily cause black stool; and borborygmus pertains to the sounds produced by the movement of gas in the intestines, not the appearance of stool.