What Are the Causes of Black Diarrhea?
Black diarrhea is often the sign of blood in the digestive tract that can have multiple causes depending on where the bleeding is coming from. Locations can range from anywhere from the nose or mouth to the colon, though bleeding lower in the GI tract tends to present as blood in the stool more than as black diarrhea. Black diarrhea caused by bleeding is called melena. Other causes include certain foods, drugs and toxins.
