Black stools
Symptoms
Related diseases
Dark, black stools indicate bleeding from the intestines. Red blood cells broken down by digestive enzymes color the stool black. The most common cause is bleeding from the upper gastrointestinal tract (e.g., stomach ulcers).
Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology