Anal fistula: Signs, symptoms and treatment options

An anal fistula is a small tunnel that forms between the end of the bowel and the skin around the anus. It typically develops following an anal abscess, which is an infected cavity filled with pus. If an abscess does not heal properly, a fistula can form as the body creates a pathway to drain the infection. Anal fistulas can cause significant discomfort and may require medical intervention to manage effectively.

What are the signs and symptoms of an anal fistula?

The symptoms of an anal fistula can vary depending on its size and the extent of infection. Common signs and symptoms include:

Pain and discomfort: Persistent pain around the anus is a typical symptom, especially during or after bowel movements, sitting or movement.

Recurring abscesses: Frequent formation of painful, pus-filled lumps near the anus may indicate the presence of a fistula.

Discharge: A key sign of an anal fistula is the leakage of pus or blood from an external opening near the anus. This discharge often has an unpleasant odour and can lead to staining of undergarments.

Swelling and redness: The skin around the fistula may become inflamed, red and tender to the touch.

Irritated skin: Constant drainage can lead to skin irritation and itching in the surrounding area.

Fever: Some individuals may experience a low-grade fever, which can indicate an ongoing infection associated with the fistula.

How is an anal fistula treated?

Most anal fistulas require surgical intervention, as they rarely heal without treatment. The type of surgery or procedure chosen depends on the complexity of the fistula and its location. Common treatment options include:

Fistulotomy: This is the most frequently performed procedure for simple fistulas. The surgeon cuts open the fistula tract, flattens it out and allows it to heal naturally. Fistulotomy has a high success rate but may not be suitable for complex fistulas that pass through significant muscle groups.

Seton placement: A seton is a thin piece of surgical thread that is placed in the fistula to help drain infection and promote healing. This technique is often used for more complex fistulas, allowing the area to heal gradually before further surgery.

Advancement flap procedure: For complex fistulas, a surgeon may use a tissue flap taken from the rectum to cover the internal opening after the fistula tract is cleared. This procedure reduces the risk of incontinence by preserving the sphincter muscles.

Fibrin glue and plugs: In some cases, non-surgical treatments such as the use of fibrin glue or biodegradable plugs are considered. Fibrin glue is injected into the fistula to seal it, while a plug can be placed to block the tract and promote healing. These methods are less invasive but may have a lower success rate compared to surgery.

LIFT (ligation of intersphincteric fistula tract): This procedure involves accessing the fistula between the sphincter muscles and sealing it to prevent further infection. LIFT is often used for fistulas that pass through the anal sphincter.

When should you seek medical advice?

If you experience symptoms such as persistent pain, recurrent abscesses or unusual discharge near the anus, it is important to consult a healthcare professional. Complications can be prevented and outcomes can be improved with early diagnosis and treatment. Imaging techniques such as MRI or ultrasound may be used to confirm the diagnosis and assess the complexity of the fistula.

Anal fistulas can significantly impact quality of life, but with the appropriate treatment, most individuals can achieve symptom relief and recovery. Your specialist will work with you to choose the best treatment option based on the characteristics of the fistula and your overall health.