There has been and continues to be a basic controversy whether fistulotomy or fistulectomy should be performed for anal fistulas. There has been only one randomized trial comparing the two techniques by Kronborg [3] who alternately assigned patients to one or the other procedure. Fistulotomy fared better due to prolonged healing time associated with fistulectomy. A small section of the tract can be excised (biopsied) if there is concern for Crohn’s disease or malignancy, in cases of long-standing fistulas. Nelson and colleagues stressed the need for taking a biopsy from recurrent abscess wall or fistula tract to exclude malignancy. Low rectal or anal cancer (adenocarcinoma) may penetrate tissue and manifest as a recurrent abscess fistula. On the other hand, a very long-standing fistula in ano may develop into a squamous cell cancer [4]. The presence of mucus in fistulous abscess should raise the index of suspicion of malignancy [5].

At the time of drainage of an abscess, the surgeon may find a fistula right away or after gentle probing with a blunt tipped probe. Primary fistulotomy was reported to be safe and with no adverse consequences in 1,000 consecutive cases [6]. Ramanujam et al. reported on 1,023 anorectal abscesses. Where the fistula was identified at the time of the incision and drainage and the experienced surgeon felt comfortable with primary fistulotomy, the results of primary fistulotomy were excellent and the recurrence rate was 3.4 % (Table 7.2) [7]. However, Vasilevsky and Gordon found fistulas in only a third of drained abscesses and argued against primary fistulotomy [8]. In any case primary fistulotomy requires an experienced surgeon exercising good judgment and extreme care in order to avoid postsurgical fecal incontinence and worse yet, recurrence due to creation of an inadvertent false passage.

Staged Fistulotomy implies that a high or complex fistula is treated in stages. At the first operation a portion of the sphincter mechanism is incised and a loose (marking) seton is placed around the remaining (undivided) external sphincter. After a period of 6–8 weeks the patient is reexamined under anesthesia and if the first stage sphincterotomy is healed by fibrosis, the remainder of sphincter is divided and the setons removed. In a study of 480 fistulotomies, Ramanujam and colleagues reported excellent healing with minimal (2 %) impairment of continence [9]. However; this report preceded the development of anorectal physiologic studies. In a larger study of staged fistulotomy using seton from the same institution Pearl and colleagues reported recurrence rate of 3 % and major incontinence, defined as the need to wear a pad, in 5 % of 110 patients treated in this fashion (Fig. 7.4) [10]. This is in contradistinction of the incidence of incontinence in cutting setons, which is reported to be as high as 12 % in a meta-analysis [11].