There are several common causes of anal bleeding with bright red blood and no pain: the first, and more common, is mixed hemorrhoids, especially internal hemorrhoids. Hemorrhoids are masses of varicose veins, which generally cause the hemorrhoidal veins to stagnate and swell when there is increased abdominal pressure or constipation, and the hemorrhoidal veins become congested. The main clinical symptom of internal hemorrhoids is blood in the stool, which is usually bright red and the blood does not mix with feces. When drinking a lot of alcohol or squatting for a long time, it can cause the hemorrhoidal veins to pool and swell, resulting in bleeding, usually in the form of spots or jets. If the hemorrhoid does not form a blood clot, there is usually no painful symptom. The second, anal bleeding without pain, may be caused by rectal polyps or rectal adenomas, where long-term stool irritation tends to damage the blood vessels under the mucosa, leading to bleeding, which can be clearly diagnosed by rectal palpation or placement of a hemorrhoid anoscope.