The causes of bright red blood from the stool may include hemorrhoids, rectal cancer, other digestive and systemic diseases. 1. Hemorrhoids: although hemorrhoids are venous plexus, but the bleeding is mostly in bright red color, mostly occurring in defecation or after defecation, usually in the form of dripping or spurting blood, with pain when hemorrhoidal nucleus is prolapsed and embedded. 2. Rectal cancer: there is fresh blood or pus blood in stool, mostly accompanied by emaciation, change of stool habit and shape, and anorectal drop. 3. Other gastrointestinal diseases: ulcerative colitis is often manifested as pus-blood stool, peptic ulcer, radiation enteritis, gastrointestinal mesothelioma, intestinal polyp ulceration, etc. can have fresh blood in stool; aortoenteric fistula bleeds fiercely, which is usually caused by aortic aneurysm and reconstruction of abdominal aorta. 4. systemic diseases: common in reoccurring anemia, leukemia, thrombocytopenic purpura and hemophilia and other blood diseases, connective tissue disease, uremia, some acute infectious diseases such as epidemic hemorrhagic fever, sepsis, etc., can lead to stool with bright red blood. Bleeding in the stool may also have other reasons, need to consult a doctor in time, comprehensive examination, standardized treatment, in order to avoid delaying the condition.