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Beverly Hills · 435 N. Bedford Dr., Suite 308Mon–Fri 9:00 am – 5:00 pmMost PPO insurance accepted
Allen KamravaMD · MBA · FACS · FASCRS

Medication

In office

Botox for Anal Fissure

A quick office injection that relaxes the tight sphincter muscle for a few months — long enough for the fissure to heal — without cutting any muscle.

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Setting
In office
Anesthesia
Usually none needed — it's a brief injection; a topical numbing agent can be used
Back to work
Most patients return to work and normal activity the same day
Pain relief
Little to none afterward — over-the-counter relievers if needed
Success rate
60-80%
Recurrence
up to 40%

What it is

What is Botox for Anal Fissure?

Botulinum toxin (Botox) injection is a non-surgical treatment for chronic anal fissures. It involves injecting Botox directly into the internal anal sphincter muscle. This procedure is also known as a 'chemical sphincterotomy.'

How does it work?

A chronic anal fissure is often perpetuated by spasm and high resting pressure of the internal anal sphincter muscle. This increased pressure reduces blood flow to the fissure, preventing it from healing. Botox works by temporarily paralyzing the injected muscle, causing the internal anal sphincter to relax. This relaxation reduces the resting pressure, improves blood flow to the fissure, and allows the tear to heal naturally.

Am I a candidate?

Who is a good candidate for Botox?

Botox injection is typically considered a second-line therapy for chronic anal fissures (those present for more than 6 weeks) that have not healed with conservative treatments like dietary changes and topical creams (such as calcium channel blockers or nitrates).

Ideal candidates include:

  • Patients who wish to avoid the risks of surgical sphincterotomy, particularly the risk of permanent incontinence.
  • Patients who have failed first-line medical therapies.
  • Patients with an increased risk of incontinence, such as women with a history of obstetric injury or individuals with pre-existing borderline continence.

How it's done

  1. 1A brief exam first — the whole visit takes only minutes.
  2. 2A small dose of botulinum toxin is injected directly into the internal sphincter muscle, usually on both sides.
  3. 3There is no incision and nothing to heal from the procedure itself — the medicine simply relaxes the muscle over the following days.
  4. 4Most patients go straight back to their day.

What to expect

  1. Same day

    Back to work and normal activity for most patients.

  2. First week

    The muscle gradually relaxes; fissure pain typically eases over several days as the pressure comes down.

  3. Following weeks

    With the pressure lowered, the fissure has its best chance to heal — and many do. Fiber, fluids, and soft stools protect it while it heals.

  4. A few months

    The effect wears off gradually and the muscle's full strength returns — by then the fissure has often healed. If it hasn't, that isn't a failure on your part — a small operation is the reliable next step. A follow-up visit checks on it.

Risks & considerations

What are the risks?

Botox is generally a very safe procedure with a low risk of serious complications. The most common side effects are temporary and mild.

  • Temporary Incontinence: The most common side effect is temporary, mild incontinence to flatus (gas) or stool seepage. This occurs in up to 18% of patients and almost always resolves as the Botox wears off, typically within 3 months.
  • Pain or Hematoma: Minor pain, bruising, or a small hematoma can occur at the injection site.
  • Urinary Retention: This is a very rare side effect.
  • Failure to Heal: The fissure may not heal, requiring further treatment.

Unlike surgical sphincterotomy, Botox does not carry a risk of permanent damage to the sphincter muscle.

The risks that matter

Every operation carries a long list of possible complications. These are the ones that are serious enough — and common enough — to understand in real numbers before you decide.

Temporary Fecal Incontinence

The most common side effect is temporary, mild incontinence to flatus (gas) or stool seepage. This occurs in up to 18% of patients and almost always resolves as the Botox wears off, typically within 3 months.

10-18%— roughly 1 in every 10-20 patients
Why it happens
The botox over-relaxes the sphincter muscles that provide our ability to control stool leakage.
If it happens
We await for the botox to wear off, typically in 3-4 months.

Lowering the odds is not the same as removing them. Even when everything is done right, this can still happen — that is the nature of the operation, not a failure of your care.

Sources

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