There may be several reasons for blood in the buttocks when wiping the stool: first, the medical history should be pursued, whether there is a history of striking, falling or foreign object injury to the anus, if there is such a history, general visual diagnosis, rectal finger diagnosis, anoscopy can be clearly diagnosed. Secondly, if the patient has anal fissure, long-term dry stool is easy to damage the skin of the anal canal, which leads to fissure, there is blood in the buttocks when wiping the stool, the blood in the stool is usually bright red, the blood does not mix with the feces, the trauma can be seen in the perianal area, and it is sometimes accompanied by pain, especially when the pain is aggravated during the bowel movement. Third, if the patient has previous hemorrhoids, especially internal hemorrhoids, is a varicose vein vascular mass, generally in the abdominal pressure increases or constipation, easy to lead to pathological hypertrophy of the anal cushion, hemorrhoidal vein stasis, swelling, hemorrhoidal vein stasis, rupture and thus the formation of fresh blood. Therefore, there are many reasons for wiping the buttocks with blood, you should actively go to the hospital to perform rectal fingerprinting, if necessary, can be placed in the anoscopy to clarify the diagnosis.