Fresh blood in the stool every other day, but the colonoscopy can not see the bleeding point, may be hemorrhoids, anal fissure and other anal canal diseases, may also be the small intestine above the part of the bleeding, need to do further examination, clear the cause of fresh blood in the stool. Hemorrhoids and anal fissures are common anal and intestinal diseases, patients can have the symptom of fresh blood in the stool, manifested as fresh blood on the surface of the stool, or blood on the paper towel after the stool, hemorrhoids can also be manifested as a spurt of blood. The diagnosis of hemorrhoids and anal fissure mainly relies on anorectal examination, colonoscopy does not check this area, there can be missed diagnosis, and therefore can not detect the bleeding point. Enteroscopy is an examination method in which the enteroscope is inserted through the anus into the ileum by following the lumen and observing the colonic lesions from the mucosal side. Bleeding above the small intestine can occur in patients who have blood throughout the stool. For patients with small amount of bleeding, it is necessary to complete the relevant examinations, such as abdominal CT, gastroscopy, small colonoscopy, etc., in order to clarify the cause and location of bleeding. When the bleeding volume is larger, it is necessary to go through the abdominal cavity exploration surgery, supplemented by endoscopy during the operation, in order to clarify the cause of the disease and treatment. If there is blood in the stool but the bleeding point cannot be detected by colonoscopy, the doctor should evaluate the patient and choose the appropriate test to identify the cause of the bleeding and assist in the treatment.