Black stool is not detoxification, there are many reasons for black stool: first, eating blood products can cause black stool, stop eating blood products for 3 days, the color of stool can become normal. Second, oral medication, such as colloidal bismuth pectin, need to stop taking drugs for 3 days, the color of the stool can become normal. The third kind, there is bleeding in the digestive tract, you can check gastroscopy to clarify the cause of bleeding, it may be gastric ulcer, gastric cancer or stomach and other diseases, which may cause bleeding, and patients with serious conditions will have symptoms such as dizziness and chest tightness. If there is black stool, you must go to the hospital in time to avoid delay.