Fresh blood in stool indicates that the bleeding site is in the rectum or anal canal, which may be caused by hemorrhoids, anal fissure, intestinal tumors and other reasons. 1. Hemorrhoids: Fresh blood in the stool may be due to the stool passing through the mucous membrane of the bulging and eroded internal hemorrhoids, scratching the mucous membrane on the surface of the hemorrhoidal nuclei, which may lead to rupture of the mucous membrane and bleeding. 2. Anal fissure: if the patient’s stool is too dry, in the process of defecation, squeezing to the anus, the formation of ulcerative wounds, so in the defecation is easy to appear defecation pain as well as the phenomenon of bleeding, the color of blood is mostly bright red. 3. Intestinal tumor: the surface of colorectal tumor is eroded, and the friction bleeds when passing stool, which leads to fresh blood in stool, and there may be pain in the lower abdomen, or the symptoms such as change in stool texture. If there is blood in the stool, it may also be caused by rectal polyps, rectal-anal trauma, coagulation disorders and other diseases. You should go to the hospital to see a doctor to find out the cause of the problem and then give targeted treatment.