Stomach pain and diarrhea black stool is mostly seen in the digestive tract bleeding, may also be caused by dietary factors. If there is a stomach pain, and accompanied by the phenomenon of black stool, most of them are caused by gastrointestinal bleeding, mostly seen in peptic ulcer with bleeding. Since peptic ulcers tend to produce too much gastric acid, when accompanied by bleeding, it is digested by the stomach and intestines and then excreted in the stool, resulting in black stool. It may also be caused by diet, such as eating too much animal blood, animal liver and other foods with high iron content, leading to indigestion, often causing stomach pain and black stools. Stomach pain diarrhea black stools need to consult a doctor in time to identify the cause and then targeted treatment.