Anal fissure surgery: sphincterotomy, botulinum toxin and what to expect

A fissure is a small tear in the skin just inside the anus, often from passing a hard stool, with sharp pain during and after a bowel movement and sometimes bright red blood. Milton Keynes explains that tightness of the internal sphincter can reduce blood flow to the tear and stop it healing, and treats a fissure that has lasted more than six weeks as chronic.

The NHS says most fissures heal alone with simple measures, and that you should see a GP if there is no improvement after seven days of self-care. Painkillers, fibre, fluids and warm baths are the first line, then prescription creams. Surgery is considered when those fail or the fissure keeps coming back, not as an early shortcut.

• Plymouth describes GTN ointment used every 12 hours for 6 to 8 weeks.

• Diltiazem cream is an alternative if GTN is not suitable.

• Lidocaine eases pain but does not promote healing.

Botulinum toxin is injected into the sphincter under anaesthetic to relax it temporarily. Guy's and St Thomas' notes that its use for fissures is unlicensed, though evidence supports it. Milton Keynes gives about a 70 per cent chance of healing, an effect lasting about three months, repeatable, with a risk of minor gas incontinence.

Lateral internal sphincterotomy cuts a small part of the inner sphincter muscle. Milton Keynes says at least 9 in 10 are cured and Plymouth says it reduces spasm and improves blood flow. The trade-off is permanence: Milton Keynes says up to 1 in 3 have poor control of gas, with some soiling or mild incontinence. For stubborn cases Plymouth mentions a flap procedure.

Guy's and St Thomas' says surgery is often a day case under general anaesthetic and that a pre-assessment clinic comes first. Expect fasting instructions, a review of medicines such as blood thinners, and a chance to ask about continence risk before you consent.

Keep stools soft beforehand with fibre and fluids; Plymouth suggests around 2 litres of fluid a day and avoiding long spells on the toilet.

You are asleep for either procedure, according to the NHS and Milton Keynes. In the botulinum approach, the surgeon injects the muscle; in sphincterotomy a small incision divides part of the internal muscle. Neither involves removing the fissure as such, because relieving spasm lets the tear heal.

Guy's and St Thomas' describes day surgery with same-day discharge. Ask what pain relief and stool-softening plan you will go home with, when you may bath, what bleeding to expect and when to restart blood thinners.

The key concern is the effect on control. Milton Keynes quotes up to 1 in 3 for poor control of gas after sphincterotomy and mentions soiling or mild bowel incontinence in some. For botulinum toxin it mentions minor gas incontinence that fades as the effect wears off. General risks include bleeding, infection and pain.

Fissures can recur: Plymouth says up to 3 in 10 people who heal with GTN have repeat episodes, and Milton Keynes says further courses or surgery may be needed for frequent recurrence.

The pages retrieved give no fixed recovery periods, so timings here are qualitative: pain usually eases quickly once the sphincter spasm is relieved, and the wound heals over the following weeks. Keep stools soft, as the NHS advises, with fibre and fluids, and use warm baths to soothe; Plymouth describes 15-minute baths.

Return to work and driving depend on comfort and on any medicines you are taking. GOV.UK says you must tell the DVLA if you cannot drive three months after an operation, and that you should ask your doctor how surgery affects driving.

Seek urgent help for heavy bleeding, severe or worsening pain, a fever, difficulty passing urine or a hot, tender swelling beside the anus. Report new leakage of stool or loss of control promptly to your surgical team. For less urgent concerns contact your GP or NHS 111, and call 999 for collapse.

• Which option do you suggest for me, and what are the local healing figures?

• What is my realistic risk of problems with wind or stool control?

• Is there any anal or bowel condition that changes your advice?

• What happens if the fissure does not heal?

• When will I be reviewed afterwards?

The operations are done the same way. NHS routes typically expect you to have tried creams first and may wait for a colorectal clinic slot, while private services can offer quicker access and choice of surgeon. Ask in both whether botulinum toxin is offered, as it is unlicensed for this use, and how repeat treatment is handled.