An anal fistula is a communication (tunnel) between the skin around the anus and the inside of the anus or rectum.
How does anal fistula originate?
The origin of anal fistula is usually secondary to obstruction of a perianal gland that produces a collection of pus (anal abscess). The anal abscess drains into the skin, leaving in half of the cases a communication between the skin and the inside of the anus.
Sometimes anal fistula occurs as a manifestation of other pathologies, such as Crohn’s disease, inflammatory bowel disease.
Anal fistula is manifested by the chronic outflow of pus or feces through the fistula orifice located in the skin of the anus.
Diagnosis of anal fistula
For the diagnosis of fistula, the most important criterion is anal exploration by a colorectal surgeon. Imaging tests such as anal ultrasound or pelvic MRI may be required.
Types of anal fistula
Anal fistulas are classified as simple or complex, depending on the degree to which the anal sphincters are affected by the fistula.
Treatment of anal fistula
Anal fistula is treated by surgery. The technique varies according to the type of fistula, the patient’s history and local conditions: history of anal surgery, inflammatory disease or other risk factors for the development of anal incontinence.
The fistula is usually simple in most cases and can be treated on an outpatient basis, staying only a few hours in a hospital center. Therefore, it is possible to return to work activities in a short period of time. When fistulas are complex, fistula treatment is more laborious and requires a good surgeon to decide which of the current techniques is the most appropriate for the patient and the fistula he/she presents.
Currently, there are treatments such as LIFT, minimally invasive surgery of the anus (plugs; tails; laser; clips)… And even, in very selected cases, using stem cells. Not all options are ideal for all fistulas and all patients, so to minimize the risk of complications (recurrence and incontinence among others), the surgeon who evaluates and treats patients should have extensive experience in this pathology.
Dr. Eloy Espín Basani
Dr. Sebastiano Biondo
Specialists in Coloproctology of Coloproctology Barcelona and members of the Spanish Association of Coloproctology.