Colorectal · London
Lateral internal sphincterotomy for chronic anal fissure, by a consultant colorectal surgeon.
The gold-standard surgical treatment for a fissure that has not healed with creams or botox - done properly, as a day-case, with a tailored technique that keeps your continence intact.
Indicative pricing
What a private lateral internal sphincterotomy costs in London.
Indicative ranges across UK private providers.
In short
£2,500–£4,000, home the same day.
| Procedure | Indicative range | Typical duration | Recovery |
|---|---|---|---|
| Lateral internal sphincterotomy (day-case, GA) | £2,500–£4,000 | 10–20 min | Same visit |
| Lateral internal sphincterotomy under LA | £2,000–£3,200 | 10–20 min | Same visit |
| Botulinum toxin injection (fissure) | £1,200–£2,200 | 15 min | Same visit |
| Examination under anaesthesia (EUA) | £1,400–£2,400 | 20 min | Same visit |
| Colorectal consultation | £220–£400 | 30 min | Same visit |
| Topical GTN or diltiazem (prescription) | £30–£80 | 6–8 wk course | From pharmacy |
Prices vary by clinic, by which colorectal surgeon does the case, and by the anaesthetic chosen.
The problem
Chronic fissures are undertreated, then overtreated.
Most fissures are either fobbed off with cream that no one explains how to use, or rushed to surgery before proper medical therapy has been tried. We do the honest middle: complete the conservative course, offer botox, and operate only when it is genuinely the right step.
-
Never had a proper cream course?
6–8 weeks of GTN 0.4% or diltiazem 2% with fibre, macrogol and sitz baths heals 50–70% of chronic fissures. If you haven’t done that properly, do it first.
-
Tried creams and still stuck?
Botulinum toxin injection is the next step - 60–75% heal, no incontinence risk, repeatable. Worth trying before surgery for most patients.
-
Time to operate?
Lateral internal sphincterotomy heals 90–95% at six weeks with recurrence under 5% - the highest and most durable healing of any fissure treatment.
When it helps
When a lateral internal sphincterotomy is the right step.
The situations we see most, plus the red flag that means gastroenterology rather than a surgeon.
-
Chronic anal fissure (>6–8 weeks)
"Cutting glass" pain during and after opening bowels, bright red bleeding on the paper, not settling with creams or fibre.
-
Sentinel skin tag + hypertrophied papilla
The classic signs of a chronic fissure - a small tag at the fissure edge and a firm papilla just inside.
-
Failed GTN or diltiazem cream
A proper 6–8 week course of topical muscle relaxants has been tried and the fissure has not healed.
-
Failed botulinum toxin injection
Botox has been tried, the fissure has come back or never healed - surgery is now the next honest step.
-
Recurrent fissure at 6 or 12 o’clock
A fissure that keeps returning in the typical posterior or anterior midline position, with visible fibrosis at the edge.
-
Anal sphincter hypertonia
A tight, spasming internal sphincter that is preventing the fissure from healing, confirmed on examination.
-
Post-obstetric fissure (cautious)
Fissures after childbirth need special care - sphincterotomy carries more incontinence risk in parous women and is tailored accordingly.
-
Red flag: atypical or lateral fissure
Multiple fissures, off-midline fissures, weight loss, diarrhoea or blood in stool point to Crohn’s - gastroenterology first, not surgery.
Procedure options
Sphincterotomy is one option - here are all of them.
What each option on the table actually involves - and which fits which patient.
-
Closed lateral sphincterotomy
A subcutaneous knife is passed through the inter-sphincteric plane and the internal sphincter is divided without opening the skin. Quick, small wound.
-
Open lateral sphincterotomy
A small linear incision exposes the internal sphincter, which is then divided under direct vision. Preferred by some units for accuracy.
-
Tailored sphincterotomy
Only the length of internal sphincter matching the fissure is divided - modern practice to reduce the risk of incontinence.
-
Traditional (dentate line) sphincterotomy
Internal sphincter divided from the dentate line to the distal end - higher healing, but higher incontinence risk than tailored.
-
Botulinum toxin injection
Non-surgical alternative - a temporary chemical sphincterotomy. Repeatable, no incontinence risk, but lower long-term healing than surgery.
-
Laser fissurotomy
A newer minimally invasive alternative that vaporises fibrosis and stimulates healing without dividing the sphincter. See laser proctology.
-
Anal advancement flap
Rarely used, reserved for very complex or previously operated fissures where a flap of healthy tissue is brought down to cover the defect.
-
Examination under anaesthesia
An EUA on its own - to confirm the diagnosis, exclude Crohn’s and plan the right operation without committing to sphincterotomy on the day.
Safety and recovery
What to expect afterwards - honestly.
Lateral internal sphincterotomy is a well-studied day-case operation with the best fissure healing rates of any option - and a real, if small, risk of incontinence that we take seriously.
-
Fissure healing 90–95% at 6 weeks
Lateral internal sphincterotomy has the best evidence of any fissure treatment. Recurrence after healing is very low, under 5%.
-
Incontinence risk - the honest bit
Incontinence to flatus or liquid stool occurs in 2–15% depending on how much sphincter is divided, gender and baseline continence. Usually mild and transient, occasionally permanent.
-
Women and parous patients: more caution
Women have lower baseline sphincter pressure and a shorter sphincter, so tailored technique matters even more. Any obstetric injury is a serious pause point.
-
No wound suturing, no dressing changes
The small wound is left open to heal. Sitz baths after opening bowels keep it clean; no stitches to remove.
-
Bleeding, infection, abscess - all rare
Minor bleeding is common; significant bleeding, infection, abscess or fistula are uncommon and the team is prepared.
-
Incomplete healing (5–10%)
A small number of fissures don’t heal fully - options are a repeat procedure, botox top-up, or moving to an advancement flap.
-
Keyhole deformity
Over-aggressive division can leave a groove that soils slightly - the reason we favour tailored sphincterotomy.
-
Not for Crohn’s fissures
A fissure caused by Crohn’s disease can be worsened by sphincterotomy.
-
Red flags after surgery
Fever, spreading redness, worsening pain after day three, or heavy bleeding are not normal - call the clinic or A&E the same day.
Reading your operation note
Your operation note in four parts. Read the last one first.
Whichever technique was used, the note the colorectal surgeon sends you keeps to the same shape.
A quiet reminder
Surgical language is precise and can read coldly - we translate it for you.
If you would like us to talk you through the note before your review, just ask.
- 01 Header
Indication and technique chosen
Why the operation was done - chronic fissure, failed medical therapy - and which technique was used (open, closed, tailored).
- 02 Technique
Anaesthetic and extent of division
Whether it was done under LA, sedation or GA, and how much internal sphincter was divided relative to the fissure length.
- 03 Findings
Fissure position, tag, papilla, IBD
Notes on where the fissure was, sentinel tag and papilla, and anything to suggest Crohn’s or an atypical cause.
- 04 Impression
Recovery, healing window, follow-up
Read this first: expected recovery, when the fissure should be healed, and whether a follow-up review is needed.
Recognised by major UK insurers
Cover for lateral internal sphincterotomy is usually funded by UK insurers when medically indicated for chronic anal fissure.
Frequently asked
Everything we get asked about lateral internal sphincterotomy.
Quick answers on pain, cost, alternatives, and the honest incontinence risk.
-
What is a lateral internal sphincterotomy?
A short day-case operation for chronic anal fissure. A small part of the internal anal sphincter is divided to release the spasm that is keeping the fissure open. It is the gold-standard surgical treatment recommended by NICE and the ACPGBI when creams and botox have not worked.
-
Why do I need one - can’t creams fix a fissure?
Most acute fissures do settle with high-fibre diet, softeners like macrogol, sitz baths and 6–8 weeks of GTN 0.4% or diltiazem 2% cream - these heal 50–70%. Botulinum toxin heals another 60–75%, though a third recur. Sphincterotomy is for the fissures that don’t heal with all of that.
-
Does a lateral sphincterotomy hurt?
During the operation you feel nothing - either the area is fully numb or you are asleep. Afterwards there is soreness for a few days, controlled with simple painkillers, macrogol and sitz baths. The fissure pain itself usually improves within the first week.
-
How much does a private lateral sphincterotomy cost in London?
Roughly £2,500–£4,000 as a day-case under GA, or £2,000–£3,200 under LA in selected units. Botulinum toxin as an alternative is £1,200–£2,200.
-
What is the risk of incontinence?
The honest answer: 2–15% of patients report some incontinence to flatus or liquid stool afterwards, depending on how much sphincter was divided, gender and baseline continence. It is usually mild and transient. Tailored sphincterotomy - dividing only the length matching the fissure - meaningfully reduces this risk.
-
When can I go back to work and exercise?
Office work in 2–5 days, no heavy lifting for two weeks. Full fissure healing takes 6–8 weeks, and 90–95% of patients are healed by then with a recurrence rate under 5%.
-
Is laser fissurotomy or botox a better option?
Different, not necessarily better. Botox is repeatable and carries no incontinence risk but recurs in about a third of patients. Laser fissurotomy is a newer minimally invasive option that doesn’t divide the sphincter. Sphincterotomy still has the highest and most durable healing rates.
-
When should I see a GP urgently?
Bloody stool with weight loss and diarrhoea, or fissures that are off-midline or multiple, are not typical fissures and point to inflammatory bowel disease - you need gastroenterology, not a surgeon. Fever, spreading redness or heavy bleeding after surgery are all reasons to seek same-day medical help.
Related treatments