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Anal Fissure: Symptoms, Causes, Treatment, Botox & Surgery

  • Prof. Dr. Zahid Mahmood
  • August 9, 2026

Anal Fissure: Symptoms, Causes, Treatment, Botox & Surgery

Medically reviewed by Prof. Dr. Zahid Mahmood, MBBS, FCPS — General, Laparoscopic & Laser Surgeon, Lahore.

An anal fissure is a small tear or ulcer in the sensitive lining of the anal canal. It commonly causes sharp pain during a bowel movement followed by burning or spasm that can last for minutes or hours. A small amount of bright-red blood may appear on toilet paper.

Most recent fissures heal with soft stool, good bowel habits and local treatment. A chronic fissure may require a sphincter-relaxing ointment, Botox or surgery.

What causes an anal fissure?

The usual trigger is trauma to the anal lining from a hard or large stool. Severe diarrhoea, childbirth and repeated local irritation can also produce a tear.

Pain causes the internal anal sphincter to tighten. This spasm reduces blood flow to the fissure and makes the next bowel movement more painful, creating a cycle of pain, fear, constipation and poor healing.

Common risk factors

  • Constipation and hard stool
  • Straining during bowel movements
  • Low-fibre diet or inadequate fluid intake
  • Repeated diarrhoea
  • Pregnancy and vaginal delivery
  • Anal trauma
  • Some inflammatory or infectious conditions

Symptoms

  • Sharp, cutting or “glass-like” pain while passing stool
  • Burning or throbbing pain lasting after the bowel movement
  • A streak of bright-red blood on stool or toilet paper
  • Fear of passing stool because of pain
  • Anal spasm or tightness
  • Itching or irritation
  • A small skin tag in a longstanding fissure

Severe pain is more characteristic of fissure than uncomplicated internal haemorrhoids. Piles and fissures can coexist.

Acute and chronic anal fissure

An acute fissure is recent and usually looks like a superficial tear. It often heals within several weeks when stool is kept soft.

A chronic fissure has persisted or repeatedly reopened. It may have thickened edges, exposed internal sphincter fibres, an external sentinel skin tag or an enlarged anal papilla inside. Chronic fissures often need treatment that relaxes sphincter spasm.

When might a fissure have another cause?

Most primary fissures lie in the posterior or anterior midline. Multiple fissures, a fissure away from the midline, unusual ulceration or poor healing should prompt assessment for another condition, such as:

  • Crohn’s disease or another inflammatory bowel disease
  • Tuberculosis
  • Sexually transmitted infection or HIV-related disease
  • Anal cancer or another tumour
  • Reduced immunity or certain blood disorders

This does not mean that an atypical fissure is necessarily cancer, but it may require examination under anaesthesia, biopsy, cultures or additional bowel investigation.

When should I seek urgent medical care?

Arrange prompt or urgent assessment for:

  • Heavy or continuous bleeding
  • Dizziness, faintness or weakness with bleeding
  • Fever, chills, pus or increasing swelling
  • Constant severe pain unrelated to bowel movements
  • A painful lump that may indicate an abscess
  • Black stool or blood mixed throughout the stool
  • Unexplained weight loss or a lasting change in bowel habit

An anal abscess can initially resemble a fissure but requires urgent drainage.

How is anal fissure diagnosed?

The pattern of pain and bleeding is often highly suggestive. Gentle separation of the buttocks may show the tear. A painful acute fissure should not be repeatedly forced open for examination.

A digital rectal examination or proctoscopy may be deferred until pain improves. Examination under anaesthesia is considered when the diagnosis is uncertain, symptoms are atypical or adequate examination is impossible.

First treatment: keep stool soft

Breaking the cycle of hard stool and pain is essential:

  • Eat more fibre from vegetables, fruit, pulses, oats and whole grains.
  • Use psyllium or another bulking agent if advised.
  • Drink adequate fluid unless medically restricted.
  • Use an osmotic laxative or stool softener when prescribed.
  • Do not delay the urge to pass stool.
  • Avoid prolonged toilet sitting and straining.
  • Walk and remain physically active.

Too much fibre without enough water can worsen bloating or constipation, so changes should be gradual.

Warm baths and pain relief

A warm sitz bath after a bowel movement can relax spasm and soothe pain. Keep the area clean with water and pat dry. Avoid strong soap, antiseptics and repeated rubbing.

Paracetamol or another suitable pain medicine may help. Codeine can worsen constipation and is usually avoided. A short course of local anaesthetic gel may be prescribed for severe pain.

Sphincter-relaxing ointments

Glyceryl trinitrate (GTN)

GTN ointment relaxes the internal sphincter and improves blood flow. It may be prescribed for several weeks. Headache and dizziness are common side effects, and GTN can interact dangerously with medicines used for erectile dysfunction or certain heart conditions.

Diltiazem or nifedipine

Topical calcium-channel blockers also relax the sphincter. Diltiazem often causes fewer headaches than GTN, although local irritation can occur. Availability and licensing vary, so these medicines should be used only under medical guidance.

Apply only the prescribed amount and complete the advised course even if pain improves earlier, because full healing takes time.

Botox injection

Botulinum toxin is injected into the internal sphincter to produce temporary relaxation, usually lasting several months. This gives the fissure time to heal without permanently dividing muscle.

Botox may be considered when ointments fail or cause side effects, and in patients where continence preservation is particularly important. Healing is less predictable than after lateral internal sphincterotomy, and recurrence or repeat injection may occur. Temporary difficulty controlling gas or stool is possible.

When is surgery considered?

Surgery may be offered for a chronic fissure that has not healed despite consistent fibre, stool-softening treatment and sphincter-relaxing medication, or when symptoms are severe and persistent.

Lateral internal sphincterotomy

Lateral internal sphincterotomy divides a carefully controlled portion of the internal anal sphincter away from the fissure. This reduces spasm, improves blood flow and has a high healing rate.

The principal concern is altered continence. Risk depends on the amount of muscle divided and factors such as age, previous anal surgery, existing leakage, multiple vaginal deliveries and sphincter injury. A tailored operation and careful patient selection are important.

Fissurectomy and advancement flap

Fissurectomy removes fibrotic edges and cleans the base of a chronic fissure. It may be combined with Botox or an advancement flap.

An advancement flap uses healthy nearby skin to cover the fissure. It can be useful when sphincter pressure is normal or low, or when sphincterotomy carries an increased continence risk.

What about laser treatment?

“Laser fissure treatment” is not one universally standard operation. Laser energy may be used by some surgeons during fissurectomy or related procedures, but it does not replace the need to treat constipation and sphincter spasm. Evidence and long-term outcomes depend on the exact technique.

The established surgical options remain carefully selected lateral internal sphincterotomy or a sphincter-preserving procedure such as fissurectomy with an advancement flap. Patients should ask exactly what procedure is proposed, its evidence, recurrence risk and continence risk.

Recovery after a procedure

Many fissure procedures are day-case treatments. Postoperative care commonly includes:

  • Prescribed pain relief
  • Fibre, adequate fluids and stool softeners
  • Warm baths and gentle cleaning with water
  • Early walking
  • Avoiding constipation and straining
  • Gradual return to work and exercise

A small amount of bleeding or discharge can occur. Seek advice for persistent heavy bleeding, fever, worsening pain, pus, difficulty passing urine or inability to pass stool or gas.

Anal fissure after childbirth

Anterior fissures are more common in women and may follow vaginal delivery. Treatment begins with stool softening and local therapy. Before sphincterotomy, the surgeon should consider possible childbirth-related sphincter injury and continence symptoms; a sphincter-preserving procedure may be preferable.

Can anal fissure return?

Yes. Recurrence is more likely if constipation, hard stool, diarrhoea or straining returns. Continue healthy bowel habits after pain and bleeding have resolved.

Common questions

Is an anal fissure the same as piles?

No. A fissure is a tear; piles are enlarged anal cushions. A fissure typically causes sharp pain, while uncomplicated internal piles often cause painless bleeding or prolapse.

Can a fissure become cancer?

A typical fissure does not turn into cancer. An atypical or non-healing ulcer may need biopsy because another condition can mimic a fissure.

Can I cure it with diet alone?

Many acute fissures heal when stool becomes consistently soft. Chronic fissures often require an ointment, Botox or surgery in addition to bowel-habit treatment.

Should I stop eating to avoid bowel movements?

No. This can worsen dehydration and constipation. Eat a balanced fibre-containing diet, drink appropriately and use prescribed stool-softening treatment.

Key message

Anal fissure causes sharp pain during defecation and a small amount of bright-red bleeding. Keeping stool soft and avoiding straining are central to every treatment. Chronic fissures can often heal with GTN or diltiazem; Botox and surgery are options when medical treatment fails. Atypical fissures, fever, swelling or heavy bleeding need prompt assessment.

Anal fissure treatment in Lahore

Prof. Dr. Zahid Mahmood can confirm the diagnosis, identify secondary causes and discuss bowel treatment, ointments, Botox, fissurectomy or lateral internal sphincterotomy according to individual continence risk.

For an appointment, call 0300 413 0159 or visit professorzahid.com.

This article provides general education and does not replace personal medical assessment. Heavy bleeding, fever, swelling, pus or constant severe pain requires urgent medical review.

Medical references

  1. Williams NS, O’Connell PR, McCaskie AW, editors. Bailey & Love’s Short Practice of Surgery. 28th ed. CRC Press; 2023. Chapter 80, “The anus and anal canal,” pp. 1428–1429.
  2. Cross KLR, et al. Association of Coloproctology of Great Britain and Ireland guideline on the management of anal fissure. Colorectal Disease. 2023.
  3. Guy’s and St Thomas’ NHS Foundation Trust. Anal fissure treatment.
  4. NICE. Chronic anal fissure and botulinum toxin type A injection.

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