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Botox for anal fissure explained

Published 13 March 2026 ·Last reviewed 13 March 2026 by the editorial team ·How we create our content

At a glance

Botox (botulinum toxin) injection is a treatment for chronic anal fissures that have not responded to conservative measures and topical treatments. It works by temporarily relaxing the internal sphincter muscle, improving blood flow, and creating a healing window. The procedure is brief, usually done as a day case, and the recovery is typically straightforward.

How it works

The mechanism is similar to topical treatments like GTN and diltiazem, but more direct and more potent:

  1. Injection into the sphincter — botox is injected directly into the internal anal sphincter muscle
  2. Muscle relaxation — the botox blocks nerve signals to the muscle, causing it to relax
  3. Improved blood flow — reduced spasm means better circulation around the fissure
  4. Healing window — the relaxation lasts two to three months, providing sustained conditions for healing

The key advantage over topical treatments: botox provides consistent, round-the-clock sphincter relaxation. Topical treatments need to be applied multiple times daily and their effect fluctuates.

The procedure

Botox for fissure is typically done as a day case procedure:

  • Duration: The injection itself takes a few minutes
  • Anaesthesia: Usually brief general anaesthesia or sedation
  • Setting: Day surgery — you arrive, have the procedure, and go home the same day
  • What happens: The surgeon injects a small amount of botulinum toxin into the internal sphincter muscle, usually at one or two sites
  • Going home: Most people leave within a few hours of the procedure

Recovery

The recovery from the injection itself is minimal:

  • Day 1 to 3: Mild soreness at the injection site. Otherwise, most people feel back to normal quickly.
  • Day 3 to 14: The botox gradually takes effect. The sphincter relaxes progressively over this period.
  • Week 2 onwards: Most people notice improvement in fissure symptoms — less pain, shorter post-bowel-movement discomfort, easier bowel movements.

The important self-care during recovery:

  • Continue stool softening (fibre, hydration, softeners)
  • Continue sitz baths
  • Do not stop the self-care routine just because symptoms improve — the fissure needs the full healing window

When botox is recommended

Botox is typically considered when:

  • Conservative measures (dietary changes, stool softening) have been tried
  • Topical treatments (GTN, diltiazem) have been tried for an adequate period and have not healed the fissure
  • The fissure is chronic (present for more than six to eight weeks)
  • The patient prefers a less invasive option than surgery

After botox

If it works

Many people describe gradual improvement over two to four weeks, followed by a period of relative comfort while the botox is active. The fissure heals during this window. If it heals completely, it may not recur — though maintaining good bowel habits remains important.

If it partially works

Some people experience improvement but not complete healing. In these cases, a second injection or escalation to surgery may be discussed.

If it does not work

Botox does not work for everyone. If there is no improvement after two to three weeks, the conversation about next steps — a second injection or surgery — typically begins. Our guide on what to do when botox does not work covers these options.

Common questions

How does botox help a fissure heal?

Botox (botulinum toxin) works by temporarily paralysing the internal anal sphincter muscle. This reduces the spasm that restricts blood flow to the fissure. With improved blood flow and reduced tension, the fissure has a better environment for healing. The effect is temporary — typically lasting two to three months — but this window is often enough for the fissure to heal.

Is the botox injection painful?

The injection is done under sedation or general anaesthesia in most cases, so you do not feel the injection itself. Some people report mild soreness at the injection site for a day or two afterwards, but most describe the procedure as surprisingly uneventful.

How long does the botox effect last?

The muscle-relaxing effect typically lasts two to three months. During this window, the reduced sphincter tension allows the fissure to heal. After the botox wears off, the sphincter gradually regains its normal tone. If the fissure has healed during this time, it may not recur.

What is the success rate of botox for fissures?

Studies and clinical experience suggest that botox heals chronic fissures in roughly 50 to 70 percent of cases. This is higher than topical treatments alone but lower than surgical sphincterotomy. Botox is often tried before surgery because it is less invasive and carries a lower risk of incontinence.

Can botox cause incontinence?

Temporary changes in gas control are reported by a small percentage of people after botox injection. Significant incontinence is uncommon and, when it occurs, is temporary — it resolves as the botox wears off. This is one of the advantages of botox over surgery: any side effects are reversible.

When to seek care Heavy bleeding or feeling faint? Get emergency help now. Emergency: 911

Not sure how urgent it is? Get help today.

  1. Emergency

    Heavy bleeding, black tarry stools, feeling faint, severe pain or trouble breathing.

    Call 911 or go to the ER.

  2. Today

    Fever, pain getting worse, a hot swollen lump, or trouble passing urine.

    Call your doctor or go to urgent care.

  3. Soon

    Bleeding or bowel changes nobody has checked, or anything lasting 3 weeks.

    Book a doctor’s appointment.

Feeling overwhelmed? Call or text 988, any time.

See all the signs

For this topic, get medical advice if you notice:

  • Heavy or persistent bleeding that does not settle
  • Severe pain that is getting worse rather than better
  • Fever or signs of infection
  • Symptoms that have not improved after 4 to 6 weeks of self-care

Recording how you feel is not the same as being checked. These are the signs that need a doctor’s attention.

Call 911 or go to the emergency room now if you have:

  • bleeding that will not stop, a lot of blood (the toilet water turns red, or you pass large clots), or any bleeding with feeling faint or dizzy
  • fainting, a racing heart or trouble breathing
  • confusion or slurred speech, extreme shivering, no urine in a day, or blotchy skin
  • sudden severe belly pain, or a swollen, hard belly with vomiting or not passing stool or gas
  • you cannot pass urine at all, or your bladder feels full and painful and you can’t empty it
  • redness, swelling or severe pain spreading quickly around your anus, genitals or groin, especially with a fever or feeling very ill
  • a fever with a painful swelling near your anus if you have diabetes or a weakened immune system (for example, from chemotherapy or transplant medicines)
  • black, tarry stools

Call your doctor or go to urgent care today (or the ER if you can’t be seen today) if you have:

  • a temperature of 100.4°F (38°C) or higher, chills, vomiting, or feeling generally unwell
  • pain that is getting worse over days, or severe pain that stops you sitting or sleeping
  • a hot, swollen or very tender lump near your anus or at the top of the crease between your buttocks, or foul-smelling discharge
  • trouble urinating
  • bleeding that is getting heavier or more frequent, or blood mixed into your stool
  • feeling much more tired than usual, looking pale, or getting out of breath more easily than you used to
  • not passing stool for several days, or new belly pain

Make an appointment with your doctor if:

  • you have never had these symptoms checked by a doctor or nurse — whatever your age
  • you have had rectal bleeding for more than 3 weeks
  • your bowel movements have been looser, thinner or more frequent than usual for 3 weeks or more, or you have lost weight without trying
  • symptoms have not settled after a week or so, or keep coming back
  • you notice a new lump near your anus, between your buttocks or in your belly, or an itch or discharge that does not clear
  • you have new leakage or trouble controlling your bowels
  • you are 45 or over, or have a family history of bowel cancer or inflammatory bowel disease, and any of these symptoms are new for you

If you are unsure, it is always reasonable to ask. If things feel overwhelming, call or text 988 (Suicide & Crisis Lifeline) or chat at 988lifeline.org, any time. If you don’t feel safe, call 911.

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Related symptoms

BleedingPain during bowel movementsPain after bowel movementsSpasm or crampingConstipation

Discreet symptom tracking

Symptoms that come and go? Keep track, day by day.

For hemorrhoids, fissures, fistulas and other anal and rectal problems. A short, discreet email asks how things have been, and saves each answer, so you can look back at every flare and every good week in your own words. If you haven’t had your symptoms checked, see your doctor first.

  • About ten seconds a check-in. No app, no password.
  • Nothing in the subject or preview says what it’s about.
  • Each Sunday, a link to your week, ready for your next appointment.
Start tracking →

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