A fistula is an abnormal tunnel running from inside the anal canal to the skin outside. It usually shows as a small opening near the anus that discharges pus or fluid, sometimes settling for weeks and then flaring up again.
The most important thing to understand is this: a fistula does not close on its own, and no medicine will close it. Antibiotics settle the infection temporarily. The tunnel remains.
Where it comes from
Most fistulas begin as an abscess. Small glands sit inside the anal canal, and if one becomes blocked and infected it forms a collection of pus. That abscess either bursts or is drained, and in a proportion of patients the track it created never fully closes.
That leftover track is the fistula. This is why many patients say the problem started with a painful swelling months or years earlier.
Less commonly, fistulas are associated with other conditions including Crohn’s disease and tuberculosis. This matters because those need treating alongside the surgery, and it is one reason a proper assessment comes before any procedure.
Why fistula surgery is not straightforward
The tunnel usually passes through or close to the sphincter, the muscle ring that controls continence. Cutting the tunnel open cures the fistula reliably, but cutting through too much of that muscle can permanently affect your control over stool and wind. Every decision in fistula surgery is a balance between clearing the tract completely and protecting that muscle.
This is the reason fistula surgery has a reputation for recurrence and for repeat operations. Surgeons who prioritise a guaranteed cure over the muscle risk incontinence. Surgeons who protect the muscle too cautiously risk the fistula returning.
Assessment comes first
Nothing should be planned until the anatomy of your particular fistula is known.
Examination and proctoscopy to find the external opening and assess the area.
MRI of the pelvis for anything other than a simple, superficial fistula. It maps the course of the tract, shows how much muscle it crosses, and identifies branches or collections that would otherwise be missed. Operating on a complex fistula without an MRI is how tracts get left behind and the problem returns.
Assessment of continence before surgery, particularly if you have had previous fistula operations, have given birth, or already notice any difficulty holding wind.
Laser closure
A fine laser fibre is passed along the length of the fistula tract. Energy delivered as the fibre is slowly withdrawn destroys the lining of the tunnel and causes it to shrink and seal along its whole length. The internal opening is closed separately.
The sphincter muscle is not divided at any point. That is the central advantage and the reason this technique exists.
The procedure takes around thirty to forty-five minutes under spinal or short general anaesthesia. Most patients go home the same day or the next morning, with a small dressing rather than an open packed wound.
Honest expectations about success
Simple fistulas do well. Complex, branching, recurrent, or long-standing fistulas have a higher chance of needing more than one procedure, whatever technique is used.
Where a fistula does not fully heal after laser closure, the options include repeating the procedure or moving to a different approach. This is not a failure of the decision to try a sphincter-preserving technique first. Attempting the muscle-sparing route before the muscle-cutting route is the correct sequence, because continence lost cannot be recovered.
You should be told before your procedure what the realistic prospect is for your specific fistula, based on your MRI, rather than a general success figure.
Setons, and why one may be placed first
A seton is a soft thread passed through the tract and left in place for a period. It sounds primitive and it is genuinely useful.
It keeps the tract draining so infection does not build up, allows inflammation to settle, and lets a complex tract mature into something that can be treated definitively and safely.
If a seton is recommended before definitive treatment, it is usually because operating immediately into an inflamed, infected field would give a worse result. It is a staged plan, not a delay.
If you have an abscess now
A rapidly developing, hot, tender swelling near the anus, often with fever and severe pain, is an abscess. It needs drainage promptly and should be seen the same day. Antibiotics alone will not resolve a collection of pus.
Drainage relieves the pain quickly. Whether a fistula develops afterwards is assessed later, once things have settled.
Recovery
Most patients return to desk work within three to seven days.
Expect some discharge from the area for the first one to two weeks as the tract seals. Sitz baths two or three times daily, stool softeners and simple dressings are usually all that is needed. There is no daily wound packing as there is after conventional laying-open surgery.
Follow-up matters here more than in most procedures, because healing is assessed over weeks and an early sign of an unhealed tract is easier to deal with than a recurrence six months later.
Risks
Recurrence or incomplete healing, the main issue with all fistula surgery, higher in complex and recurrent cases.
Continuing discharge for a period after the procedure, which is usually part of normal healing.
Infection or abscess formation if a segment of tract remains.
Bleeding, usually minor.
Effect on continence, substantially lower than with muscle-dividing techniques since the sphincter is not cut, but no anal procedure carries zero risk.
Frequently asked questions
Can a fistula heal with medicines?
No. Antibiotics settle infection and reduce discharge temporarily, but the tunnel remains and the problem returns. A fistula needs a procedure.
Will surgery affect my control over motions?
Laser closure does not divide the sphincter muscle, which is precisely why it is used. That risk is much higher with techniques that cut through the muscle. Raise any existing difficulty with control before your procedure.
Do I need an MRI?
For anything other than a simple superficial fistula, yes. It maps the tract and identifies branches. Planning complex fistula surgery without it risks leaving part of the tract behind.
Can it come back?
Yes, and recurrence is more common with complex, branching or recurrent fistulas than with simple ones. Repeat treatment or a different approach is then considered.
Why has my surgeon put in a thread instead of treating it?
That is a seton. It keeps the tract draining and lets inflammation settle so that definitive treatment gives a better result. It is a planned stage, not a delay.
How long will I be off work?
Usually three to seven days for desk work. Some discharge continues for a week or two afterwards.
I have had fistula surgery before and it came back. Is anything different possible?
Often yes. Recurrent fistulas need fresh mapping with an MRI and a plan based on what was done before. Bring your previous operation notes and any earlier imaging.
Consultation
Dr. Ripudaman Singh Lubana holds a Fellowship in Minimal Invasive Proctology from IMMAST, Mumbai, and has performed over 500 laser proctology procedures. Sphincter preservation is the guiding principle in fistula work, since continence lost cannot be restored.
He consults at Doctor Square Hospital on VIP Road Zirakpur, Trinity Hospital in Zirakpur, Curasia Hospital in Dhakoli, and Adesh Medical College Hospital in Mohri, Ambala Cantt.
Bring any previous operation notes and imaging. Call 8054173528 to arrange a consultation.
This page is for patient education. It is not a diagnosis or a treatment plan. A painful anal swelling with fever needs same-day assessment. Every patient is examined and assessed individually, and the treatment plan is built around the individual fistula.
