Anal swelling may be due to proctitis, perianal abscess, rectal prolapse, rectal tumors and other diseases, the causes are different, the treatment is different. 1. Proctitis: proctitis is an acute and chronic inflammatory disease of the inner wall of the rectum caused by a variety of reasons, which can lead to anal distension and other symptoms, treatment can be prescribed to use mesalazine, salicylazosulfapyridine, dexamethasone and other medications for treatment, but also the use of bifidobacteria, etc. for treatment. 2. Perianal abscess: perianal abscess is a kind of acute suppurative infectious disease occurring in the soft tissues around the rectum and anal canal or its surrounding interstitial space, this disease can also lead to the symptoms of anal swelling, the treatment can be surgical incision and drainage of pus, but also follow the doctor’s instructions to use metronidazole, oxfloxacin, and other medicines to carry on the anti-infective treatment. 3. Rectal prolapse: Rectal prolapse is a kind of disease in which the wall of rectum is partially or completely displaced downward, and this disease can lead to the symptoms of anal distension, and it can be treated by injecting phenol vegetable oil and aqueous solution of quinine hydrochloride and urea into the submucosal layer of the prolapsed area, and it can be treated by surgical resection of prolapsed part. 4. Rectal tumor: in the early stage of rectal cancer, due to the tumor cells invading perianal tissues, there will be anal swelling, accompanied by frequent bowel movement and incomplete defecation, which needs to be operated as soon as possible to clean up the tumor foci completely, in order to improve the discomfort of anal swelling. In addition to the above diseases, other diseases can also lead to the symptoms of anal distension, the cause is complex, it is recommended that patients go to the hospital in a timely manner to find out the cause, and be treated as soon as possible under the guidance of a professional doctor.