What Is an Anal Fistula? Symptoms, Causes and Treatment

Main Keywords: anal fistula, anal fistula treatment, fistula in ano, anal fistula surgery

Main Keywords: anal fistula, anal fistula treatment, fistula in ano, anal fistula surgery

Supporting Keywords: anal fistula symptoms, anal fistula causes, anal discharge, infection around the anus, anal fistula MRI, complex anal fistula, fistulotomy, seton treatment, LIFT procedure, anal abscess and fistula, recurrent anal abscess

An anal fistula is an abnormal tunnel that forms between the skin around the anus and the anal canal — a channel that should not normally exist. Most anal fistulas develop after an anal abscess caused by infection of the glands in the anal region.

Patients typically present with recurrent swelling, pain or discharge around the anus, or with a history of a previous anal abscess.

An anal fistula usually does not heal completely on its own. The main aim of treatment is to eliminate the fistula tract while preserving, as far as possible, the anal muscles that provide bowel control.

What Causes an Anal Fistula?

Infection of the small glands within the anal canal can lead to an anal abscess. After the abscess drains — spontaneously or surgically — a channel may remain in some patients between the site where the infection began and the skin around the anus. This channel is called an anal fistula.

A significant proportion of anal fistulas are related to a previous anal abscess. More rarely, fistulas can be associated with inflammatory bowel diseases such as Crohn’s disease, previous operations, trauma or other conditions.

Evaluating underlying causes is particularly important in recurrent or complex fistulas.

What Are the Symptoms of an Anal Fistula?

Anal fistula symptoms can vary from patient to patient.

The most common complaints are:

Recurrent swelling around the anus

Purulent or foul-smelling discharge from around the anus

Constant or intermittent staining of underwear

Irritation and itching around the anus

Discomfort when sitting or during bowel movements

Recurrent anal abscess attacks

Pain and fever when an abscess develops

In some patients, a small opening may be visible at the edge of the anus, from which discharge appears from time to time.

What Is the Difference Between an Anal Abscess and an Anal Fistula?

An anal abscess and an anal fistula are related but different conditions.

An anal abscess is a collection of infection and pus in the tissues around the anus. It usually presents with sudden-onset pain and swelling.

An anal fistula is the abnormal channel between the anal canal and the skin that usually forms after this infection and persists.

Put simply: the anal abscess is the acute phase of the infection, and the anal fistula is the chronic channel that develops in some patients as a continuation of this process.

How Is an Anal Fistula Diagnosed?

The patient’s history and examination of the anal region are very important in diagnosing an anal fistula.

The external opening of the fistula may be visible on examination. However, the starting point of the fistula inside the anal canal and its relationship to the anal muscles cannot always be determined by external examination alone.

Imaging methods such as pelvic MRI can be helpful, particularly in complex anal fistulas, recurrent fistulas or patients who have had previous surgery.

Knowing the relationship of the fistula tract to the anal sphincter muscles is important for correct treatment planning.

What Are Simple and Complex Anal Fistulas?

Anal fistulas are divided into different groups according to the path they follow and their relationship to the anal muscles.

Some fistulas are superficial and follow a simpler course, while others can pass through or around the anal sphincter muscles, which play an important role in bowel control.

For this reason, not every anal fistula is treated the same way. Particularly for fistulas involving a significant portion of the anal muscles, the aim of treatment is not only to eliminate the fistula but also to preserve anal sphincter function.

Do Anal Fistulas Heal on Their Own?

Anal fistulas usually do not heal completely on their own.

The occasional closing of the external opening does not necessarily mean the disease has resolved. If infection persists within the channel, swelling and abscess can develop again.

For this reason, patients with recurrent anal abscesses or persistent anal discharge need to be evaluated.

How Is an Anal Fistula Treated?

Anal fistula treatment is determined by the type of fistula, its location, its relationship to the anal muscles and the patient’s previous operations.

Some of the methods that can be used in treatment are:

Fistulotomy

Seton placement

Sphincter-preserving surgical methods

The LIFT procedure

Various fistula closure methods in suitable patients

The choice of method is not made in a standardized way. The anatomical structure of the fistula is evaluated and treatment is planned individually for each patient.

What Is a Fistulotomy?

Fistulotomy is one of the surgical methods used for suitable, superficial anal fistulas. It is based on opening the fistula tract and allowing it to heal.

However, in patients whose fistula tract passes through a significant portion of the anal muscles, performing a fistulotomy can pose a risk to bowel control, and other methods may need to be preferred.

What Is Seton Treatment?

A seton is a special material passed through the fistula tract.

It can be used particularly in certain complex fistulas involving the anal muscles, to keep the infection under control and to manage the fistula safely.

The type and duration of seton placement can vary according to the structure of the fistula and the planned treatment.

Can an Anal Fistula Recur?

The disease can recur after anal fistula treatment.

The likelihood of recurrence can vary according to the anatomy of the fistula, whether it is complex, previous treatments and any underlying diseases.

For this reason, correct evaluation of the fistula anatomy before surgery is particularly important in complex fistulas.

When Should You See a General Surgeon?

If, around the anus, there is:

Recurrent swelling,

Purulent discharge,

Foul-smelling discharge,

Recurrent abscesses,

Pain,

An opening at the edge of the anus that does not close,

a General Surgery evaluation for anal fistula is advisable.

The aim of anal fistula treatment is not only to treat the fistula tract but also to preserve the anal muscles and bowel control function as far as possible.

Frequently Asked Questions