MRI has been found to accurately delineate the presence and course of a primary fistulous track, and also demonstrates the presence and site of any secondary extensions and accompanying abscess. MR imaging allows identification of infected tracks and abscesses that would otherwise remain undetected. Furthermore, radiologists can provide detailed anatomic descriptions of the relationship between the fistula and the anal sphincter complex, thereby allowing surgeons to choose the best surgical treatment, significantly reducing recurrence of the disease or possible secondary effects of surgery, such as fecal incontinence. MRI is considered the “gold standard” for imaging fistula anatomy. It provides excellent soft tissue resolution in multiple planes without the need for ionizing radiation. It is indicated for all recurrent fistulas and primary fistulas that appear to be complex after examination under anesthesia or endoanal ultrasound. Unfortunately, some patients have implants that preclude MRI or they find the procedure intolerable.