If the patient has blood in the stool but the colonoscopy is normal, there are two possibilities: First, if the patient has blood on the surface of the stool and the colonoscopy is normal, it is likely that there are hemorrhoids and anal fissures, which are diseases of the anal canal, and the colonoscopy does not check this area, so there is a missed diagnosis, you need to do a finger anal examination to clarify, after the diagnosis can be treated with Ma Yinglong hemorrhoid cream nanoanal. If the patient has blood in the stool, but the colonoscopy is normal, the patient is considered to have bleeding above the small intestine and needs to have an electronic gastroscopy or small intestine microscopy. If the patient has pain or discomfort in the upper abdomen, electronic gastroscopy is needed. If the electronic gastroscopy also does not find any bleeding point, and the patient does routine blood test to clarify that there is bleeding, small intestine microscopy is needed to clarify.