[Fistulas and fissures. Part I: perianal fistulas].

Perianal abscesses are caused by cryptoglandular infections at the dentate line between the anal sphincters. Acute therapy will relieve the pain but not the development of perianal fistulas. The challenge in therapy of perianal fistulas balances between the best possible cure and the preservation of continence. Local treatment with fibrin glue is a first step whenever continence might be endangered by operative procedures. First results with fistula "plugs" are promising but need further critical observation. Lower, intersphincteric fistulas can be treated by fistulotomy without risking a substantial loss in continence, but higher, suprasphincteric or complex fistula systems might be treated as a first step with a seton--followed by surgery as a second step. Excision of the external fistula tract, closure of the internal opening, and a local advancement flap are now competing with fistulotomy, curettage, and immediate reconstruction.