Understanding anal fistula

An anal fistula is something which causes discomfort, pain and embarrassment for those affected. Mr Andrew Brian Williams, a general and colorectal surgeon with a special interest in anal fistula explains everything you need to know about the condition, including treatment options.

What is an anal fistula?

An anal fistula is an abnormal connection or tunnel that forms between the anal canal (the last part of the intestine) and the skin surrounding the anus. It often occurs as a result of an infection or abscess in the anal glands or nearby tissues.

When an infection develops, it creates a passageway for fluid and pus to drain, which leads to the formation of the fistula. Often the first sign of a problem is the development of an abscess around the anus which may spontaneously drain or need surgical attention. Following this, the external wound does not heal but continues to discharge brown/yellow offensive fluid.

Anal fistulas can vary in size, depth, and complexity. They can have one or multiple openings, and their course may be straight or branched. Fistulas can occur in different positions around the anus, such as in the anal canal itself, near the anus, or in the buttock crease.

What are the symptoms of anal fistula?

The most common symptom is the presence of a persistent, pus-filled discharge from an opening near the anus. It can also result in pain, swelling, itching, and discomfort during bowel movements.

What are the treatment options?

There are various surgeries available to treat anal fistula. The choice of repair surgery for anal fistula depends on several factors, including the complexity and location of the fistula.

The first stage of any treatment is to ensure that the collection around the fistula is draining effectively and then every effort is made to simplify the path of the fistula to render it in an optimal state for closure. This often involves the insertion of a drainage thread (seton) to facilitate complete drainage of any infected fluid.

Fistulotomy

A fistulotomy is the most popular choice for straightforward low fistulas. An incision is made, which opens the entire length of the fistula, allowing the tract to heal from the inside out. It promotes general healing and is effective overall, but can cause some temporary discomfort during the recovery period. Clearly, the track of a fistula traverses some of one or both of the anal muscles that we rely on to maintain bowel control. Dividing this muscle can have detrimental effects on this control and so an accurate anatomical assessment must be undertaken before any muscle is cut. Much of Mr Williams’ research has been focused on predicting the effects of potential muscle division around the anus.

Fistula Plug

A fistula plug is often a popular choice for more complex or recurrent fistulas. During the procedure, a biocompatible material, using porcine collagen is inserted into the fistula tract to close the tunnel. The plug encourages the growth of new tissue over some time, resulting in the sealing of the fistula.

The success of this procedure may vary and, in some cases, multiple procedures may be required.

LIFT

The LIFT (ligation intersphincteric fistula tract) procedure involves the creation of a new wound around the anus to gain access to the gap between the inner and outer anus muscles (sphincters). The fistula tract traverses this space and so is amenable to division and closure with stitches. This effectively disconnects the fistula from the internal opening which is driving the infection. If successful, the fistula then heals over and the new external wound heals.

What is the recovery period after surgery?

After undergoing anal fistula surgery, patients are typically advised to maintain good hygiene practices, including regular cleaning of the wound site. Healing time varies depending on the complexity of the surgery and individual factors.  Often when the fistula treated is very complex, drainage of the infection may require quite extensive wounds around the anus. These may initially need quite close attention and often packing in the postoperative period.

Pain management is an essential part of the healing process. Following the procedure, patients may suffer from discomfort and pain, especially during bowel movements. The healthcare provider may prescribe pain medication or suggest over-the-counter pain relievers to manage the pain.

It is also important to make some dietary changes. Eating a balanced diet rich in fibre and drinking plenty of fluids can help soften the stools, reducing strain during bowel movements.

The patient will also require some follow-up appointments, with a specialist in order to monitor the healing progress. They may need to remove any remaining sutures or evaluate the success of the surgery.

Mr Andrew Brian Williams is a highly-experienced consultant general and colorectal surgeon based in London. If you would like to book a consultation with Mr Williams, you can do so today via his Top Doctors profile.