How treat a boil on anus?

Get checked!: Your boil (= abscess) may represent the opening of a fistula, an abnormal infected tunnel that will need surgery to fix and prevent serious problems down there, so get it looked at by an experienced surgeon asap, .

Anal Abscess: An anal abscess is a painful condition in which a collection of pus develops near the anus. Most anal abscesses are a result of infection from small anal glands. http://www.webmd.com/a-to-z-guides/anal-abscess