A hard lump in the buttock groove near the anus may be associated with perianal abscess, hemorrhoids, warts, boils, folliculitis and other conditions. 1. Perianal abscess: manifested as a protruding hard lump around the anus, part of which can be pushed and is accompanied by severe pain, and the lump forms a pus cavity filled with purulent secretions. 2. hemorrhoids: hard things in the anus may be thrombosed hemorrhoids, manifested as purple-red bumps, accompanied by inflammation bumps will gradually increase, accompanied by severe pain, itching and other symptoms. 3. Condyloma acuminatum: If the bumps are corns, cauliflower patterns or papillae, and the color of the bumps is grayish-white, painful, and accompanied by a bad smell, it may be condyloma acuminatum. 4. Boils: If they are lumps protruding from under the skin, they may be boils caused by Staphylococcus aureus infection and are mildly painful. 5. Folliculitis: If the hair in the area is infected, it can cause inflammation of the hair follicles, which will be red, swollen, painful and raised. Due to the complexity of the cause, patients should go to the anorectal department in time, follow the doctor’s instructions for systematic examination, to clarify the cause of the disease, and give reasonable treatment.