Bleeding in the stool should be alerted to the possibility of many more diseases than just four. Common are hemorrhoids, intestinal polyps, chronic colitis, intestinal malignant tumors and so on. Hemorrhoids are caused by varicose veins of the anorectal veins, varicose veins, defecation is likely to bleed rupture bleeding, resulting in blood on the surface of the stool. Intestinal polyps are rich in localized capillaries, often leading to blood on the surface of the stool. Chronic colitis, such as ulcerative colitis, intestinal ulcer trauma blood vessels exposed, in the stool under the stimulation can also cause stool bleeding, mostly dark red bleeding. In addition, intestinal malignant tumors can also cause local tissue damage, resulting in blood vessel rupture bleeding and stool pattern abnormality. Bleeding in the stool may also be caused by anal fistula, anal fissure, coagulation disorders (e.g. hemophilia, primary thrombocytopenic purpura, etc.), intestinal parasitic diseases (e.g. hookworm disease), and trauma. Therefore, after the discovery of bleeding in the stool should be promptly to the hospital, complete the examination and diagnosis to be appropriate treatment, to avoid delaying the condition.