Bleeding hemorrhoids: lighter cases have blood on the toilet paper after defecation, heavier cases have blood drop by drop when defecating hard, and more serious cases have bleeding in the form of jets. When bleeding without discomfort, sometimes a soft spherical swelling is felt at the anus, which can be pushed back into the anus gently, bleeding hemorrhoids are caused by dry stool rubbing the blood vessels. Bleeding from anal fissures: When wiping with toilet paper after defecation, there is blood, usually not too much. It is often accompanied by anal tearing pain whenever there is a bowel movement. Perianal abscess, anal fistula bleeding: A lump around the anus with severe pain, only one side of the buttocks can sit on a chair, and larger abscesses are often accompanied by fever. The abscess should be incised and drained in time, if the draining is not complete, it will recur and form an anal fistula with constant discharge of pus and blood, which requires surgery. Colon and rectal polyps bleeding: the bleeding is not too much, mostly seen on toilet paper after the stool, sometimes not, such as the lower end of the rectum long-tipped polyps can be seen in the swelling with defecation out of the anus, and then can be retracted, intestinal polyps should be surgically treated to prevent malignant change. Rectal cancer: common change in bowel habits, constipation and diarrhea alternately, and there is always the feeling of unclean stool, pus and blood stool is common, should promptly seek medical attention. All of the above diseases are related to dry stools or constipation. The key to prevention is to avoid constipation, to develop the habit of regular bowel movement every day, to drink more water, to reduce prolonged sitting and to increase exercise appropriately.