Here we discuss a number of other common anorectal conditions: anorectal abscesses and fistulae, pilonidal disease, rectal prolapse, pruritus ani, and anal masses. For each, we outline the typical symptoms and physical findings and review appropriate management strategies.
If you encounter an anorectal disease for which you are unsure of the diagnosis, or if a patient's complaint does not respond to conventional treatment, consider biopsy of the lesion (if one is present) or referral to a specialist.ANORECTAL ABSCESSES AND FISTULAE
Anorectal infections may present acutely as abscesses or chronically as fistulae. Anorectal abscesses result from inflammation of the crypts and glands around the dentate line and spread to various locations (perianal, intersphincteric, ischiorectal, supralevator). Although a cryptoglandular origin is most common, other causes to consider include Crohn disease and a history of previous anorectal surgery.
Abscesses. Patients often present with throbbing or aching pain, swelling, drainage or bleeding, constipation, urinary difficulty, and/or fever. Physical examination usually reveals an erythematous, fluctuant, indurated mass that is tender to palpation (Figure 1).
Treatment consists of anesthesia of the overlying skin, followed by abscess drainage via a cruciate incision (Figure 2). Antibiotics are unnecessary in the treatment of anorectal abscesses except in the setting of sepsis, cellulitis, immunocompromise, or recent prosthesis. Keep in mind that only about 50% of abscesses heal after drainage; the remainder result in anorectal fistulae.
Fistulae. Fistulae are the natural sequelae of drained anorectal abscesses that have not healed completely. Anoscopic evaluation typically reveals an internal opening within a crypt near the dentate line, and perineal inspection reveals an external opening in the skin. In the operating room, the fistula tract can often be demonstrated by introduction of a fistula probe (Figure 3). Fistulae can be classified based on their anatomic course in relation to the internal and external anal sphincters. The 4 types of fistulae are:
Surgical treatment is the mainstay of fistula management and includes fistulotomy, seton placement, mucosal advancement flaps, and fibrin glue injection.