A perianal fistula is a passage between the anal gland and the skin. A fistula typically results from a perianal abscess that has been drained. It can also result in a recurring abscess, if the outer opening heals first, blocking drainage from the healing gland.
A perianal abscess forms when a gland in the anal canal becomes infected from bacteria or feces. Patients who suffer from constipation, diarrhea, or other intestinal problems are often more likely to develop a perianal abscess. The abscess is drained through a small hole near the anus. When drainage continues for several months, a doctor may diagnose a patient with a perianal fistula.
If the patient is still fighting an infection, a doctor must wait until it clears before treating the fistula itself. Perianal fistulas often cause pain and itching around the anus, and the patient may notice a bloody or pus-like discharge from the anal cavity. The doctor may use a fistula probe to examine and find the openings of the fistula to determine treatment.
In some cases, perianal fistulas heal on their own, with very little medical intervention. Doctors will often place a seton, a length of suture, inside the fistula to keep it open while it heals. Surgery is necessary when the outside opening starts to heal first, or if a doctor is concerned about allowing the fistula to heal on its own.
The surgical procedure for treating a perianal fistula usually involves cutting into the sphincter muscle to open the passage and join the external and internal openings. This allows the fistula to heal from the inside out and prevents further complications. As an alternative, some doctors inject it with a dissolvable glue or plug that closes the opening and allows it to heal.
The recovery period after a perianal fistula is sealed or surgically treated is usually free of complications. Many patients experience pain and discomfort for several days following the procedure, which can be treated with over-the-counter or prescription pain relievers. Soaking the anal area in warm water three or four times a day can help soothe the area and promote healing. Stool softeners can help prevent excess discomfort from bowel movements during the healing process.
It is important for patients to seek medical treatment for perianal abscesses and fistulas as soon as possible. This will often maximize the success of treatment. Most patients do not have problems with recurring abscesses or fistulas if they seek appropriate treatment as soon as they notice a problem.