What is the diagnosis and treatment for an anal fissure?

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Last updated: May 13, 2025View editorial policy

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From the Guidelines

For the treatment of anal fissures, conservative measures including warm sitz baths, increased fiber intake, adequate hydration, and stool softeners should be initiated first, with surgical lateral internal sphincterotomy considered only after 8 weeks of non-operative management if the fissure is non-responsive 1.

Treatment Approach

The primary goal of treatment is to break the cycle of pain, sphincter spasm, and reduced blood flow that prevents healing.

  • Conservative measures such as warm sitz baths for 10-15 minutes several times daily, increased fiber intake (25-30g daily), adequate hydration (at least 8 glasses of water daily), and stool softeners like docusate sodium (100mg twice daily) should be started initially.
  • Topical nitroglycerin ointment (0.2-0.4%) applied to the anal area 2-3 times daily for 6-8 weeks or calcium channel blockers like diltiazem (2%) ointment applied 3 times daily for 6-8 weeks can be used to relax the anal sphincter and improve blood flow.
  • For pain management, acetaminophen or ibuprofen can provide relief.

Surgical Intervention

  • Surgical treatment with lateral internal sphincterotomy is recommended in the chronic phase if non-operative management fails after 8 weeks 1.
  • This approach has a higher patient satisfaction, lower recurrence rate, and a healing rate of over 90% compared to other surgical techniques.
  • Both open and closed lateral internal sphincterotomy have similar results, although open lateral internal sphincterotomy may be associated with higher post-operative pain and delayed wound healing.

Key Considerations

  • Maintaining soft, regular bowel movements is crucial for both treatment and prevention of recurrence.
  • The choice of treatment depends on the chronicity of the fissure, the severity of its symptoms, and the rate and completeness of its response to conservative care 1.

From the Research

Definition and Presentation of Anal Fissure

  • Anal fissure (AF) is the second most common anorectal complaint in healthcare settings 2
  • The presentation might be acute or chronic, characterised by severe pain with defaecation that persists for one to two hours 2
  • The aetiology of AF is unclear, although it is commonly associated with local trauma or associated chronic conditions 2

Treatment Options for Anal Fissure

  • Non-surgical and surgical interventions are available based on the severity and persistence of the fissure 2
  • Acute AF is first treated with conservative therapy, including dietary fibre and sitz baths 2
  • Addition of topical nitrates, topical calcium channel blockers or botulinum toxin injection is indicated with failure of conservative treatment or at medical discretion 2
  • Surgical options are considered if AF persists despite treatment 2
  • Botulinum toxin is a more effective nonsurgical treatment compared to topical nitroglycerin ointment 3
  • Medical therapy for chronic anal fissure, currently consisting of topical glyceryl trinitrate, botulinum toxin injection or the topical calcium channel blockers nifedipine or diltiazem, may be applied with a chance of cure that is marginally better than placebo 4

Comparison of Treatment Options

  • Glyceryl trinitrate (GTN) ointment has an efficacy of up to 68% in healing chronic anal fissure, but it is associated with headache as the major and most common side effect 5
  • Botulinum toxin injected into the anal sphincter healed over 80% of chronic anal fissures, but it is more invasive and expensive than GTN therapy 5
  • Diltiazem ointment achieved healing of chronic anal fissure comparable to 0.2% GTN ointment but was associated with fewer side effects 5
  • The combination of nifedipine and botulinum toxin was superior to nitroglycerin and pneumatic dilatation with respect to both healing and recurrence rate 6

Efficacy and Safety of Treatment Options

  • No medical therapy came close to the efficacy of surgical sphincterotomy, though none of the medical therapies in these RCTs were associated with the risk of incontinence 4
  • Chronic anal fissures can be simply and effectively treated medically without the risk of incontinence associated with sphincterotomy 6
  • Topical nifedipine and botulinum toxin injections are an excellent combination, associated with a low recurrence rate and minimal side effects 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Anal fissures: An update on treatment options.

Australian journal of general practice, 2024

Research

Non surgical therapy for anal fissure.

The Cochrane database of systematic reviews, 2012

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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