What does it mean if i have tarry stools?

Blood or meds: Blood from high up in your digestive tract can cause black tarry sticky stools. This blood could come from swallowed blood from a nosebleed, an ulcer or other stomach problems, or bleeding in the intestine. The digestive chemicals turn the blood black and sticky and tarry. Alternatively, certain medicines like pepto-bismol can also turn your stools black and tarry. See your physician.