What is the initial treatment for anal fissure?

Initial Treatment for Anal Fissure

The initial treatment for acute anal fissure should begin with conservative management including fiber supplementation, adequate fluid intake, warm sitz baths, and topical analgesics, which heals approximately 50% of acute fissures within 10-14 days. 1, 2

First-Line Conservative Approach

Dietary and Lifestyle Modifications

• Increase fiber intake through age-appropriate foods or fiber supplements to soften stools and reduce mechanical trauma during defecation 3, 2
• Ensure adequate fluid intake to maintain soft stool consistency and prevent constipation 3, 2
• Add stool softeners if dietary modifications alone are insufficient 3

Symptomatic Relief Measures

• Apply warm sitz baths to relax the internal anal sphincter and promote healing 3, 2
• Use topical anesthetics (lidocaine 5%) for pain control, which helps break the pain-spasm-ischemia cycle 1
• Integrate common pain killers (paracetamol or ibuprofen) if topical anesthetics provide inadequate pain relief 1

Pharmacologic Treatment When Conservative Management Fails

If the fissure persists beyond 2 weeks despite conservative management, escalate to pharmacologic therapy:

Preferred Agent: Topical Calcium Channel Blockers

• Topical diltiazem or nifedipine are the most effective medical therapies with healing rates of 65-95% 1, 2
• The recommended formulation is 0.3% nifedipine with 1.5% lidocaine applied three times daily 4
• Continue treatment for at least 6 weeks, with pain relief typically occurring after 14 days 1, 4
• CCBs are superior to glyceryl trinitrate with fewer side effects (less headache and hypotension) 1

Alternative Agent: Glyceryl Trinitrate

• Topical GTN 0.2% applied twice daily achieves healing rates of 25-50% but is associated with frequent headaches 2, 5, 6
• GTN causes reversible chemical sphincterotomy by reducing maximum anal resting pressure and increasing anodermal blood flow 5, 6
• This option is less preferred than CCBs due to lower efficacy and higher side effect profile 1

Critical Pitfalls to Avoid

• Never perform manual dilatation due to unacceptably high risk of incontinence (temporary incontinence up to 30%, permanent incontinence up to 10%) 1, 4
• Avoid surgical sphincterotomy in acute fissures - surgery should only be considered for chronic fissures unresponsive after 8 weeks of conservative management 3, 2
• Do not use botulinum toxin injections in acute fissures - insufficient evidence supports this approach in the acute setting 1

Special Considerations

Topical Antibiotics

• Consider adding topical metronidazole in cases of poor genital hygiene or reduced therapeutic compliance 1
• One study showed significantly better healing rates (86% vs 56%) when metronidazole was added to lidocaine compared to lidocaine alone 1

Atypical Presentations Requiring Further Evaluation

• Fissures not located in the posterior midline require evaluation for Crohn's disease, inflammatory bowel disease, HIV/AIDS, tuberculosis, syphilis, or malignancy 3, 2
• Signs of chronicity (sentinel tag, hypertrophied papilla, fibrosis, visible internal sphincter muscle) warrant more aggressive treatment approaches 3, 2

Treatment Timeline and Follow-up

• Most acute fissures heal within 10-14 days with conservative management alone 3, 2
• Reassess at 2 weeks - if no improvement, initiate topical CCBs 3
• Continue pharmacologic therapy for 6-8 weeks before considering the fissure chronic 2, 4
• Recurrence rates approach 50% even after successful medical healing, emphasizing the importance of maintaining dietary modifications 5, 7