What is the reason for drinking red wine black stool

Normal stool is yellow, if found black stool is abnormal, more common in upper gastrointestinal bleeding. If there is no other uncomfortable performance, stool color after drinking red wine turns black, consider red wine caused by stool color change. Mainly due to the formation of minerals and iron deposition in stool and large intestine to form black stool. Also closely related to red wine contains grape pigment, need to observe whether black stool persists. If red wine is caused by people who stop drinking stool color will recover, if combined with upper abdominal discomfort, stop drinking still black stool, need to be alert to upper gastrointestinal bleeding and gastric mucosal bleeding, peptic ulcer bleeding and other closely related.