There are especially many reasons for wiping the buttocks with blood: 1. The more common reason is anal fissure, which is formed when the stool is dry and easy to stab the skin around the anus. Conservative treatment should be given, if necessary warm salt water or 1:5000 potassium permanganate sitz bath, and then topical application of hemorrhoid cream, such as taining suppository, taining cream, compound cornic acid ester. 2, if there are hemorrhoids, especially internal hemorrhoids, there will also be blood when wiping the buttocks, because hemorrhoids are the varicose vein mass, if after increased pressure, spicy diet or a lot of alcohol, the nucleus of the hemorrhoid is prone to swelling, which leads to 3, the cause of blood in the stool may also be rectal polyps, rectal adenomas, rectal malignant tumors, generally when the symptoms are heavy, easy to invade the rectal mucosa or submucosal blood vessels and lead to bleeding. So there are many reasons for blood in the stool, and there are also many types of blood in the stool, so you need to do anal diagnosis and, if necessary, perform anoscopy or colonoscopy to clarify the causes, and then treat the symptoms.