Table 1.

Commonly used fistula classifications

Parks	SPTF	St. James Hospital
1- Intersphincteric Simple intersphincteric fistula Intersphincteric fistula with a high blind track Intersphincteric fistula with a high track opening into the lower rectum High intersphincteric fistula without a perineal opening High intersphincteric fistula with a pelvic extension 2- Transsphincteric fistula Uncomplicated Transsphincteric fistula with a high blind track 3- Suprasphincteric fistula 4- Extrasphincteric fistula	Simple Complex Track crossing more than 30%–50% of the external sphincter (high-transsphincteric, suprasphincteric, and extrasphincteric) Anterior fistula in a female Multiple tracks Recurrent fistula Preexisting incontinence Local irradiation Crohn’s disease	Grade 1: Simple linear intersphincteric fistula Grade 2: Intersphincteric fistula with an abscess or secondary tract Grade 3: Simple linear transsphincteric fistula Grade 4: Transsphincteric fistula with an abscess or secondary tract in the ischiorectal or ischioanal fossa Grade 5: Supralevator or translevator disease

SPTF, standard practice task force.