The main feature is that the color of the stool is blood red, and the blood and stool are not mixed together. 2, anal fissure bleeding, anal fissure caused by bleeding stool, the main feature is bright red blood in the stool, and the blood has the phenomenon of outflow, sometimes when wiping the buttocks with hand paper See there is blood, if the anal fissure is fresh, there will be pain in the anus after the stool. 3, bleeding caused by digestive tract diseases, the main feature is the discharge of stool is tarry or black-red, bleeding site in the upper gastrointestinal tract. If the blood color of the bleeding stool is red, it is usually bleeding from the lower gastrointestinal tract. 4. Bleeding caused by rectal cancer, the blood in the stool is bright red and the blood is in the form of drops.