First, it may be a perianal abscess, such as an anal gland infection that extends along the anal canal to the perianal skin, which may lead to painful swelling at the anal opening, and it usually takes the formation of pus as the main symptom. Secondly, the painful swelling at the anal opening may be due to anal fissure, such as dry stool that can easily damage the skin around the anus and cause fissures, and the anal opening feels swollen and painful when defecating. Third, if it is a heavy mixed hemorrhoid, it may also lead to anal pain, possibly after eating stimulating food and drinking a lot of alcohol, mixed hemorrhoids congestion, swelling, poor venous reflux, long-term bruising will lead to thrombosis, there will be anal pain at the entrance. You need to use medication, such as tylenol suppositories, tylenol cream, and if necessary, perform a mixed hemorrhoidectomy.