Anal Fistula
An anal fistula can cause persistent discharge, discomfort and recurrent infection, and it rarely heals on its own. Professor Arulampalam assesses and treats patients with anal fistula in Colchester and central London, with a particular interest in minimally invasive techniques that aim to treat the fistula while protecting the muscles that control your bowels.
What is an anal fistula?
An anal fistula is a small tunnel that connects the inside of the anal canal to an opening on the skin near the anus. Fistulas vary considerably. Some are short and simple, passing through little or none of the anal sphincter muscle, while others are more complex, with a longer course, branches or more than one external opening. The type of fistula you have has an important bearing on which treatment is most suitable.
Causes and the link to anal abscess
Most anal fistulas develop after an anal abscess, which is a collection of pus near the anus. Abscesses usually begin with an infection in one of the small glands inside the anal canal. When an abscess bursts or is drained, it may heal completely, but in some people a tunnel remains between the gland and the skin, forming a fistula.
Less commonly, a fistula may be associated with other conditions, such as Crohn's disease or other inflammatory conditions, previous surgery or radiotherapy in the area. Part of your assessment is to look for any underlying cause that may influence your treatment.
Symptoms of anal fistula
Symptoms vary from person to person and may come and go. You may notice:
- Discharge of pus, blood or fluid from an opening near the anus
- Irritation, itching or soreness of the skin around the anus
- Pain or throbbing, which may worsen when sitting or opening your bowels
- Swelling that builds up and then eases when it drains
- Recurrent abscesses in the same area
- A raised temperature or feeling unwell if infection develops
Diagnosis: examination, MRI and EUA
Diagnosis begins with a discussion of your symptoms and a careful examination of the area, which helps to identify the external opening and the likely course of the fistula.
An MRI scan of the pelvis is often recommended, as it can show the path of the fistula, its relationship to the sphincter muscles and any associated abscess or branching tracts. In many cases an examination under anaesthetic (EUA) is also needed. This allows the fistula to be assessed in detail while you are comfortable, and in some patients a seton, a soft thread or loop, may be placed through the fistula to allow it to drain and settle before definitive treatment.
Treatment options for anal fistula
Treatment depends on the type and complexity of your fistula, the amount of sphincter muscle involved, your bowel function and your general health. Treatment options may include:
- Seton placement: a loop placed through the fistula to control infection and allow drainage, either as a temporary step or as longer-term management.
- Fistulotomy: opening the tract so that it heals from the base, which may be suitable for some low fistulas involving little muscle.
- Sphincter-preserving techniques: procedures designed to close or treat the tract without dividing the sphincter muscle, which may include VAAFT and laser fistula closure.
- Other surgical repairs: for some complex fistulas, other approaches may be discussed depending on your assessment.
Your doctor will explain which options are appropriate for you, together with their likely benefits, risks and chances of success.
Video-assisted anal fistula treatment (VAAFT)
VAAFT is a minimally invasive technique in which a very thin camera, called a fistuloscope, is passed into the fistula through its external opening. This allows the tract and any side branches to be seen directly from the inside. The lining of the tract is then treated and cleaned, and the internal opening is closed.
Because VAAFT does not involve cutting through the sphincter muscle, it aims to reduce the risk to continence and to avoid large external wounds. It may be particularly useful for complex or recurrent fistulas. As with all fistula treatments, there is a possibility that the fistula may persist or recur, and some patients need more than one procedure.
Laser fistula closure
In laser fistula closure, a fine laser fibre is passed along the fistula tract. The laser energy is applied as the fibre is slowly withdrawn, causing the tract to shrink and close. The internal opening is usually closed as part of the procedure.
This technique is designed to preserve the sphincter muscle and usually involves small wounds, which for some patients may mean less discomfort after surgery. It is not suitable for every type of fistula, and healing rates vary. Your doctor will discuss with you whether laser closure, alone or combined with other techniques, may be appropriate for your fistula.
Protecting continence
The anal sphincter muscles allow you to control your bowels, and protecting them is a central part of planning fistula treatment. Some treatments that divide muscle may offer a higher chance of healing but carry a greater risk of affecting continence, while sphincter-preserving techniques aim to reduce this risk but may have a higher chance of recurrence.
Balancing these factors is an individual decision. Before any treatment, your doctor will discuss your bowel control, any previous surgery or childbirth that may be relevant, and the potential effect of each option, so that you can make an informed choice.
Recovery after anal fistula treatment
Most fistula procedures are carried out as day cases, and many patients go home on the same day. You may have some discomfort, discharge and minor bleeding for a period afterwards, which can usually be managed with simple pain relief, regular warm baths or showers and keeping the area clean.
Many people return to light activities and desk-based work within a few days, although this depends on the procedure and on how you are feeling. Keeping your stools soft helps to reduce strain on the area. Your doctor will arrange follow-up to check on your healing, and you should get in touch if you notice increasing pain, swelling, fever or heavy bleeding. Possible complications include infection, bleeding, delayed healing, recurrence of the fistula and, less commonly, changes in bowel control.
Anal Fistula FAQs
Will an anal fistula heal on its own?
It is uncommon for an established anal fistula to heal without treatment. Symptoms may settle for a time, but the tunnel usually remains and infection can return, so an assessment is worthwhile if your symptoms persist.
Is an anal fistula the same as an abscess?
No. An abscess is a collection of pus, while a fistula is a tunnel that may remain after an abscess has drained. The two are closely linked, and some people develop a fistula after an abscess.
Why might I need an MRI scan?
An MRI scan can show the course of the fistula and how it relates to the sphincter muscles. This information helps in choosing a treatment that balances the chance of healing with the protection of continence.
Am I suitable for VAAFT or laser treatment?
This depends on the type of fistula, any previous treatment and your general health. After examination and imaging, your doctor will advise whether a minimally invasive technique may be suitable for you and discuss the alternatives.
Can an anal fistula come back after treatment?
Yes, recurrence is possible after any fistula treatment, and the risk varies with the type of fistula and the procedure used. Some patients need more than one procedure, and your doctor will discuss the likely outlook for you.
Book an appointment for anal fistula
If you are troubled by discharge, pain or recurrent abscesses near the anus, Professor Arulampalam sees patients for assessment in Colchester and central London, and you can book an appointment online or view the practice locations and contact details to arrange a consultation at the location that suits you best.
Please speak to your GP or seek urgent medical advice if you develop severe pain, a high temperature, heavy bleeding or feel generally unwell.