The main causes of anal bleeding after the patient’s stool are as follows: 1. Internal hemorrhoid bleeding: a common symptom of hemorrhoids, patients mainly show bleeding or jet bleeding after the stool drip, some patients bleed less, only show a little blood on the toilet paper after the stool. The color of the blood is all bright red or light red, and there is usually no mucus. Internal hemorrhoids bleeding, but also accompanied by internal hemorrhoids prolapse or anal swelling and other symptoms; 2, anal fissure bleeding: patients with blood in the stool, will be accompanied by anal pain, for tear-like pain, will make patients feel painful discomfort. This pain is cyclical, and usually occurs when the patient is defecating and the anal fissure is propped open, resulting in blood in the stool and anal pain, and after defecation, muscle spasms can cause pain again; 3. Intestinal cancer: it occurs in middle-aged and elderly people, i.e. people over 45 years old, and the blood in the stool is dark red and smells bad, mixed with mucus. Patients with such symptoms are recommended to go to a regular hospital and do colonoscopy to clarify the presence of colorectal polyps and tumors, and if necessary, pathological tests are needed to identify them.