An anoscope is used for anal exposure. I prefer the Pratt bivalve speculum for most of my proctologic cases (Fig. 12). The probe is advanced from the external to the internal opening until it clearly protrudes into the anal canal (Fig. 13). Electro­cautery (thermal cautery) is used to divide the tract over the probe. Care is taken to divide the tissue in a perpendicular fashion, avoiding a tangential oblique dissection which leads to more muscle division (Fig. 14). Once the division of the fistula is completed into the lumen of the anus, the immediate tissue surrounding the fistulous tract is infiltrated with additional 0.5% bupivacaine anesthetic to create a buffer dissection plane between the epithelialized tract and the adjacent sphincter muscle (Fig. 15). Using fine tip tenotomy scissors and tooth forceps (Fig. 16), the epithelialized tract is separated from the surrounding muscular cuff for a precise dissection with minimal damage to the anal sphincter (Fig. 17). The excised tissue is sent for histopathologic evaluation. The mucosal aspect of the internal opening and surrounding glands is fulgurated with electrocautery (Fig. 18). In order to reduce the wound size, the edge of the skin is marsupialized to the center of the wound using a running 2.0 Vicryl (polyglycolic acid) suture from the distal anus to the anoderm portion of the wound (Fig. 19). At the completion of the marsupialization, the wound center is open to promote adequate drainage and minimize the risks of postoperative sepsis (Fig. 20).