Anorectal abscess is a common infectious condition treated by colorectal surgeons. The infection originates from a gland within the anal canal. Further classification of the type of anorectal abscess is dependent on its anatomic location. Common presenting symptoms include anorectal pain, tenderness, swelling, redness, fever, or difficulty with urination. Evaluation includes a clinical examination by a colorectal surgeon. Additional diagnostic imaging with CT scan or MRI may be required if the abscess is higher up in the rectum. The initial treatment of anorectal abscess involves incision and drainage of the affected area. This can either be performed in an office setting under local anesthetic or in the operating room depending on the anatomic location of the abscess. Urgent surgical consultation should be obtained in the immunosuppressed patient which includes diabetics, patients taking immunosuppressive medications, patients on chemotherapy and patients with HIV/AIDS.
After the drainage of an acute anorectal abscess, approximately 30-50% of patients will develop a chronic sinus tract called a fistula-in-ano. A fistula can lead to persistent drainage from the anal area and recurrence of the anorectal abscess. If a fistula is suspected, the patient should be evaluated by a colorectal surgeon.
Again, the initial evaluation will include a thorough history and an in-office examination. Additional studies may include CT scan or MRI of the pelvis or an endoanal ultrasound. There is a wide range of surgical treatment options for fistula-in-ano. The treatment will be determined by the location of the fistula and how much of the anal sphincter muscle is involved.
Fistulotomy, or simply opening up the fistula tract, is the most definitive and straight forward treatment for anal fistula. This is commonly performed as long as the surgery will not damage the anal sphincter muscles.
Complex anal fistulas which are either recurrent or involve a significant portion of the anal sphincter muscles require a multi-step surgical approach. Your colorectal surgeon can place a seton through the fistula tract. This is essentially a very small rubber drain that will prevent abscess recurrence and allow the fistula tract to heal with the goal of performing a fistulotomy in the near future.
Other treatments that may be offered for complex anal fistula include fibrin glue injections, fistula plugs, mucosal advancement flaps or the LIFT procedure.
The primary goal in the treatment of fistula-in-ano is to eliminate bothersome drainage, prevent abscess recurrence and preserve anal sphincter function. The best treatment for your anorectal abscess or fistula-in-ano can be decided upon after thorough evaluation and discussion with your colorectal surgeon.