A perianal fistula is an abnormal tract between the anal canal and the skin. Treatment is individualised to its course and sphincter involvement: from simple fistulotomy to sphincter-preserving techniques (seton, LIFT, flap).
What does it involve?
It treats an anal fistula by eliminating the abnormal tract. The critical factor is how much sphincter the fistula crosses, as this determines the safest technique.
When is it needed?
It is indicated for a symptomatic fistula (recurrent abscess, discharge, irritation). A fistula does not close on its own and surgery is the definitive solution.
Preparation
A clinical assessment is done and, for complex/high fistulas, an MRI or endoanal ultrasound for precise mapping of the course and its relation to the sphincter.
How it's done
For simple, low fistulas a fistulotomy (laying open the tract) is done. For complex/high ones, where continence is at stake, sphincter-preserving techniques are used: seton, LIFT or advancement flap, often in stages.
Fistulotomy
Laying open the tract for low fistulas — high cure with minimal sphincter involvement.
Seton
A thread that drains and matures the fistula, protecting the sphincter — often an interim step.
LIFT / Flap
Techniques that close the fistula without cutting the sphincter — for high/complex fistulas.
Recovery
Recovery depends on the technique. Local wound care and sitz baths are needed; for complex fistulas treatment may be staged, with an interim seton.
Risks & outcomes
The two key goals are avoiding recurrence and protecting continence — which often trade off against each other. Choosing the right technique, guided by mapping, minimises both.
Frequently asked questions
Will my continence be affected?
For complex/high fistulas, sphincter-preserving techniques (seton, LIFT, flap) are used precisely to protect continence.
Why might several stages be needed?
In complex fistulas, a seton matures and drains the fistula first, so the definitive operation can be done more safely at a second stage.
Will the fistula close on its own?
No — an established fistula does not close without surgery and tends to recur as an abscess.
Is an MRI needed?
For complex or recurrent fistulas, MRI helps with precise mapping and choosing the right technique.