The swelling visible around the anus, it has a special number of causes: 1. It may be an anal gland infection, which spreads along the recto-anal canal to the perianal skin to form an abscess, the fluctuation is usually positive, and the perianal ultrasound can be clear. If the abscess is close to the anus, the tip will easily come out of the anus under the stimulation of stool, and the soft mass will be easily produced by the long-term inflammation. The actual fact is that you can find a lot of people who are not able to get a lot of money for the purpose of the actual money. When constipation and diarrhea increase, the anal cushion is prone to pathological hypertrophy and downward movement. If the embedded time is longer, the local hemorrhoidal vein is stagnant and swollen, easily forming a thrombus, which is harder to touch and more intense pain.