Patients with black stool, consider three causes, according to different etiology to give the appropriate treatment, as follows: First, improper diet: eat a lot of greasy, high-protein food, slow evacuation of stool, may appear black stool. At this time to give a light diet, eat more fresh fruits and vegetables, avoid the intake of high-protein foods, can be alleviated. Second, the consumption of certain drugs or food: there is a stool staining, such as oral bismuth, iron, Chinese medicine, or eating animal blood, animal offal stool color change, after stopping the above triggers, the stool color will turn yellow or yellow-green. Third, gastrointestinal bleeding: If black stool appears for gastrointestinal bleeding and the daily bleeding volume is at least greater than 50ml, seek medical attention immediately and give comprehensive treatment to protect the gastric mucosa, inhibit gastric acid secretion and reduce portal vein pressure under the guidance of the doctor to stop bleeding.