Bleeding from stool may be caused by symptoms such as anal fissure, hemorrhoids, ulcerative colitis, colorectal polyps, rectal cancer and cirrhosis of the liver. 1. Anal fissure: Anal fissure is a kind of fissure on the surface of the narrowest anal canal tissue in the section of digestive tract outlet from the dentate line to the anal rim, and the patient will have anal pain, blood in stool and constipation. 2. Hemorrhoids: patients will experience pain and bleeding when having bowel movements. 3. Ulcerative colitis: Ulcerative colitis is a chronic non-specific inflammatory disease of the colon and rectum, in which patients may experience abdominal pain, blood in stool and weight loss. 4. Colorectal polyp: Colorectal polyp is a round or oval-shaped swelling with a tip on the mucous membrane of anal canal or rectum, and the dry and hard stool will damage the mucous membrane on the surface of the polyp and lead to blood on the stool. 5. Rectal cancer: Rectal cancer refers to malignant tumors from the dentate line to the junction of rectosigmoid colon, patients will have blood in stool and anal swelling. 6. Liver cirrhosis: patients with liver cirrhosis will have serious decrease of liver function, which will lead to decrease of liver’s ability to synthesize coagulation factors, and the patients will have the symptom of bleeding in stool, meanwhile, liver cirrhosis can lead to varicose veins of esophagogastroduodenal vein, which will lead to the symptom of blood in stool. In addition, upper gastrointestinal ulcers, digestive tract tumors, gastritis, coagulation disorders, etc. may lead to blood in the stool, so when the patient bleeds in the stool, he should go to the hospital in a timely manner to improve the examination, to clarify the cause of the disease and actively cooperate with the treatment.