There are several causes of blood in the stool: 1, more common is hemorrhoids, blood in the stool is characterized by fresh color, more or less amount, usually when there is no obvious pain; 2, there is anal fissure, anal fissure blood in the stool is characterized by fresh color, defecation accompanied by severe anal tear-like pain, usually accompanied by symptoms of constipation; 3, colon polyps will also have blood in the stool, blood in the stool is generally characterized by a relatively small amount, accompanied by 4, ulcerative colitis will also have blood in the stool, usually accompanied by abdominal pain, pus and blood, and mucus and blood stool symptoms; 5, in patients older than 40 years old, can not ignore the possibility of colorectal tumors, the general blood in the stool is characterized by dark color, sometimes if the location of very low tumors, may appear fresh blood in the stool color, usually accompanied by recent changes in bowel habits, weight loss, etc., so the appearance of blood in the stool, Therefore, patients with blood in stool should go to the anorectal department of regular hospital for examination at the first time, and it is better to do e-colonoscopy for clear diagnosis and corresponding treatment.