The intestine near the anus belongs to the lower rectum, and the symptoms of pain in this area are mainly internal hemorrhoids, rectal prolapse, sinusitis, and perianal abscess, and the treatment of pain caused by different causes is different. First, internal hemorrhoids can cause pain in the anus, mainly caused by the enlargement of the nucleus as well as edema, and should be treated surgically, which can be used to cure them by surgically peeling off the nucleus. Secondly, bacterial or viral infection causes damage to the rectal mucosa, which leads to rectal prolapse. Rectal prolapse should be surgically repositioned and the necrotic rectal mucosa must be surgically removed. Acute inflammatory lesions resulting in perianal abscesses can also cause pain in the anus, and should be treated by surgical incision and drainage, where the abscess is cut open to release the fluid inside, and then stitched up after anti-inflammatory treatment.