An anal fistula can either be a single tunnel or, occasionally, a network of tunnels. It’s usually caused by an infection near the anus.
An anal fistula is a painful and often unpleasant long-term (chronic) condition. Symptoms include discharge, skin irritation and, in some cases, bowel incontinence.
You’re more likely to develop an anal fistula if you’ve had an anal abscess, including a perianal abscess. About one in every two people with an anal abscess also develops an anal fistula.
An anal fistula requires fistula treatment, usually anal fistula surgery.
The main symptoms of an anal fistula are:
See your GP if you’re regularly experiencing any of the symptoms of an anal fistula. Your GP will ask about your symptoms and your general health, including any history of bowel conditions. Your GP may examine your anus.
If your GP diagnoses - or suspects - an anal fistula, they’ll refer you to a consultant called a colorectal surgeon. At your first appointment, your consultant may refer you for further investigations, including:
An anal fistula is often the result of an anal abscess (perianal abscess). As the abscess drains, it creates a tunnel through the skin tissues between the rectum and the anus.
An anal fistula can also be caused by long-term (chronic) bowel conditions, including Crohn’s disease and diverticulitis. Very occasionally, tuberculosis (TB) and HIV infection can cause an anal fistula.
Anal fistula treatment almost always involves anal fistula surgery to close the tunnel. This allows an anal fistula to heal without affecting your bowel continence.
Your consultant will discuss your options with you but these may include: