Dark stool may be caused by bleeding in the upper digestive tract (stomach and duodenum) due to conditions like duodenal or gastric ulcer, esophageal varices, gastritis or any disease that may cause bleeding like hemophilia, tuberculosis, reduced platelet counts etc. Constipation, certain medications like iron supplements, bismuth, aspirin or other NSAIDs, or foods like black licorice or blueberries may also produce dark stools. You should consult your doctor for the identification of the cause and early treatment.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.