A black, tarry feces, usually indicates the presence of digested blood in the intestines, or to internal bleeding that has passed into the intestine. Melena is the terms commonly used to describe this condition and is typically seen due to bleeding in the upper gastrointestinal tract. The dark color of the blood is due to the oxidation of iron in the hemoglobin as it passes through the small intestine and colon.
Melena is indicative of an underlying disease and the accompanying symptoms and treatment would be based on the causative disease.
In cases with gastrointestinal bleeding symptoms may include vomit containing blood, lack of appetite, weight loss, weakness, pale mucous membranes, and anemia.
In cases with bleeding in respiratory tract symptoms may include nose bleed, sneezing, coughing up blood, pale mucous membranes, anemia, weakness, and dyspnea.
In cases with blood clotting disorders, nose bleed, blood in urine, blood in eye, anemia, pale mucous membranes, and weakness may be seen.
