Hello, I couldn t possibly know why your doctor prescribed you duphalac. What is kind of alarming is the black color in your stool. Blood in the stomach and proximal part of the intestine gets digested and gives a black (like tar) color to the stool. The stool has a different odor than usual and is soft, perhaps even like diarrhea. Sometimes when the quantity of lost blood is high, you may see some blood in the stool (colored like sour cherry). In the most severe cases of peptic ulcer bleeding, symptoms precede the stool. There could be symptoms of hypotension like faintness, thirst, cold sweating etc. In mild cases it is possible that no symptoms at all appear. In ANY case, if there s suspicion of peptic ulcer bleeding you need an endoscopic testing of your upper gastrointestinal system which includes the esophagus, the stomach and the duodenum. Duphalac and other similar drugs are NOT indicated for bleeding ulcers. I hope I ve given you a direction! Should you need further guidance, please let me know! Kind Regards!