There are many reasons why men bleed when they poop: the first, more common is likely to be hemorrhoids, hemorrhoids can be divided into internal and external hemorrhoids, which are varicose vein masses that are easily caused by increased abdominal pressure or constipation. If a man drinks a lot of alcohol or eats a lot of stimulating food, such as pepper, it can cause the hemorrhoid plexus to expand and stagnate and the hemorrhoid veins to rupture and cause bleeding. The second, if long-term constipation, dry stool, difficult to defecate, will lead to anal canal skin fissures, the formation of anal fissures will also be manifested in the stool when the blood is bright red, feces does not mix with the blood in the stool. Thirdly, if there are rectal polyps, rectal adenomas or even rectal malignant tumors, they can also erode the mucosa and the blood vessels under the mucosa thus causing bleeding. So men bleed during defecation for many reasons, and should be combined with medical history rectal finger diagnosis, and if necessary, anoscopy should be performed to clarify the diagnosis.