What is the reason for the black and green stool?

Stool black green may be caused by eating a lot of dark green food or animal blood, such as pig blood, duck blood, etc., can also be caused by taking some drugs; may also be caused by gastrointestinal bleeding diseases, such as gastric ulcer, duodenal ulcer, etc. If the stool is black green, and accompanied by other uncomfortable symptoms, you can go to the hospital for gastroscopy and enteroscopy.