If there is blood on the paper after a bowel movement, it may be an anal fissure, hemorrhoid or intestinal cancer, as follows: 1. Anal fissure, mostly caused by abnormal stool, inflammatory stimulation and anatomical defects, will drip blood during defecation, and there is blood on the paper after a bowel movement, which is bright red; patients usually do not have heavy bleeding, and the amount of bleeding is related to the degree of fissure; it is often accompanied by pain during a bowel movement, because there are rich nerve endings around the anus. The main symptom is blood in the stool, dripping blood or blood on the paper during the stool; there is pain when blood clots or inflammation occurs, which can be treated with medication, and if the treatment is ineffective, surgery is needed; 3, rectal or colon cancer, blood covers the surface of the stool, and the bleeding will gradually increase as the tumor increases.