What causes black stool?

Answer by  bananaboat (321)

One of the main causes for black stool is iron supplementation. It could possibly be that. Your stool could also be black if you eat a lot of blueberries or blackberries. Another reason might possibly be that you are bleeding internally, and for that you need to see your doctor.

Answer by  cindy (1484)

If one of the medications you are taking is Peptobismol or iron both of these commonly cause black stool. Another cause of black stool is blood in the upper part of the digestive system. The digestion of the blood is what causes it to appear black. The medical term for this is melena.