Bleeding from the digestive tract that passes through the anus is called blood in the stool. The color of blood in the stool is bright red, dark red or black, the bleeding is relatively small and does not cause a change in the color of the stool, it requires an occult blood test to be available for determination, if positive, it is called occult blood. The causes of blood in the stool can be divided into three main categories: the first category is upper gastrointestinal bleeding (such as bleeding from the esophagus, stomach, duodenum, etc.); the second category is lower gastrointestinal bleeding (such as intestinal tuberculosis, intestinal tumors, intestinal polyps, hemorrhoids, anal fissures, enteritis, etc.); the third category is systemic diseases (such as leukemia, hemophilia, sepsis, certain vitamin deficiencies, etc.), the clinical manifestations are related to the site of bleeding and the size of the bleeding The third category is systemic diseases (such as leukemia, hemophilia, sepsis, certain vitamin deficiencies, etc.), with clinical manifestations related to the site of bleeding and the amount of bleeding, such as bloody stools, mucopurulent stools, watery stools, tarry stools, abdominal pain, urgency, fever, etc. The specific treatment should be based on clinical symptoms, stool color or physical examination to determine the site of bleeding and the amount of bleeding to determine, sometimes need to determine the bleeding site through gastrointestinal microscopy, after the comprehensive judgment of the specialist to develop a reasonable treatment plan.