Perianal abscess and fistula-in-ano are two related disorders that affect the anal region. Almost all abscesses develop when one of the glands lining the anal canal becomes blocked and leads to an infection. If left untreated, the abscess can develop into a fistula. A fistula is an abnormal connection between the anal canal — through some or all of the sphincter muscle — and the skin. A small number of abscesses and fistula-in-ano occur are due to other disorders, such as inflammatory bowel disease. In addition, women may develop fistula after difficult childbirth.
Symptoms of fistula can include pain, fever, redness, or drainage of purulence (pus), bloody discharge or stool from around the anus. Some patients note a full, tender swelling or bump as the first sign. Patients may also notice difficulty controlling passage of gas or stool or soiling of their undergarments.
Treating a fistula or abscess requires proper knowledge of anal and rectal anatomy. The first step is for a colorectal surgeon to perform a careful exam and control infection by draining any abscesses. This can be performed as an outpatient procedure with a local anesthetic, although more complex cases require exam under anesthesia in the operating room. If abscess drainage is successful, antibiotics usually are not required. A colonoscopy may be necessary if the diagnosis is unclear or if an underlying disorder is suspected.
Fistulas often require surgery. In order to achieve complete healing, they may require staged or sequential treatment. After a careful examination, our experts will discuss treatment options with you and recommend the best option based on the location of the fistula and amount of involved muscle.