Perianal fistulas.

The most common cause of anal fistula is anal gland sepsis, resulting in formation of anorectal abscess, particularly if the latter allowed bursting spontaneously or has been inadequately opened at operation. Surgical treatment of the fistula must intent to its healing or simply its drainage or its transformation to a simpler one. Superficial, low transsphincteric and intersphincteric fistulas are treated by the lay-open technique. The use of a loose seton allows time for any sepsis and induration to settle before a decision about further treatment is made. Also, the use of a tight seton in the management of complex fistula may avoid an early muscle division before any tissue scarring happened. The patient with a perianal fistula must have a steady trustful relationship with his surgeon and must be fully informed on the therapeutic plan and reassured for a favourable outcome.