Causes stool bleeding blood bright red painless, generally indicates that the bleeding site in the rectum, common causes are internal hemorrhoids, rectal polyps and anal papilloma, etc.. 1. Internal hemorrhoids: internal hemorrhoids patients in the stool, if excessive force or dry stool and intestinal wall repeated friction, can cause internal hemorrhoids mucous membrane damage, stool will be mixed with bright red blood, but there is no obvious pain. 2. Rectal polyps or tumors: patients with rectal polyps or tumors, the surface of the rectal mucosa has a protruding sarcoma-like foreign body, which can occupy the position of the intestinal lumen, resulting in narrowing of the intestinal lumen. During defecation, the feces can easily scratch or squeeze the adenoma, which can cause the surface of adenoma to break and bleed, so there will be bright red blood in the stool, but there is usually no pain. 3. Anal papilloma: The fibrous connective tissue of the anal papilla due to infection, trauma and other causes of benign proliferation, and then form anal papilloma. This will lead to narrowing of the anus, and the anal papillae will easily rupture and bleed due to friction with the stool when pulling out the stool. The anal papillae are not rich in nerves, so they are usually painless. Bleeding blood in the stool is bright red and painless, it may also be coagulation dysfunction leading to rectal mucosal injury, or rectal mucosal trauma and other conditions. In this case, you need to consult a doctor in time, and after diagnosis, the professional doctor will deal with it according to the specific situation.