What are the treatment options for anal fissures?

Treatment of Anal Fissures

Start with conservative management for all anal fissures, escalate to topical calcium channel blockers (diltiazem) if no improvement after 2 weeks, and reserve lateral internal sphincterotomy for chronic fissures that fail 8 weeks of medical therapy. 1

Initial Conservative Management (First 2 Weeks)

Conservative care heals approximately 50% of all anal fissures and should be the initial approach for all patients 2, 1. This includes:

• Fiber supplementation to soften stools and reduce mechanical trauma 2, 3
• Adequate fluid intake to maintain soft stool consistency 2, 3
• Warm sitz baths to relax the internal anal sphincter and improve blood flow 2, 3
• Topical analgesics (lidocaine) for pain control, which reduces reflex sphincter spasm and enhances healing 3, 1
• Stool softeners if dietary changes prove insufficient 3

Acute fissures are more likely to heal than chronic ones with conservative care alone, and most acute fissures heal within 10-14 days 2, 4.

Second-Line: Topical Pharmacological Therapy (After 2 Weeks)

If conservative management fails after 2 weeks, add topical medications 3, 1:

Preferred Option: Calcium Channel Blockers

• Topical diltiazem or nifedipine are the preferred topical agents with healing rates of 65-95% 3, 1
• These agents are as effective as glyceryl trinitrate but with significantly fewer side effects 1
• They work by reducing internal anal sphincter tone and improving local blood flow 5

Alternative Option: Glyceryl Trinitrate

• Healing rates of 25-50%, substantially lower than calcium channel blockers 3, 1
• Headaches are a common side effect that limits patient compliance 3
• This option has fallen out of favor due to inferior tolerability 5

Adjunctive Considerations

• Metronidazole may be added in cases of poor genital hygiene, though evidence is limited 1

Third-Line: Botulinum Toxin Injection

For fissures that fail topical therapy, botulinum toxin injection should be considered before surgery 1:

• Cure rates of 75-95% with low morbidity 1
• Works by causing temporary sphincter relaxation 1
• Less invasive than surgery with reversible effects 6

Surgical Management: Lateral Internal Sphincterotomy

Surgery should only be considered for chronic fissures non-responsive after 8 weeks of conservative management 3, 1:

• Lateral internal sphincterotomy (LIS) is the gold standard surgical procedure with the highest long-term success rates 2, 7
• Surgery is appropriate for chronic/complicated fissures, acute fissures with severe pain unresponsive to medical therapy, or recurrent fissures despite optimal treatment 7
• LIS carries a risk of irreversible anal incontinence, which is why it must be reserved for refractory cases 7

Surgical Contraindications

• Avoid surgery for acute fissures in children and most adults 3, 1
• Manual dilatation is strongly contraindicated due to high risk of temporary and permanent incontinence 3, 1, 7

Critical Diagnostic Considerations

Red Flags Requiring Further Evaluation

• Off-midline fissures mandate evaluation for Crohn's disease, HIV/AIDS, ulcerative colitis, tuberculosis, syphilis, leukemia, or cancer 2, 3
• Most fissures occur in the posterior midline; atypical locations are pathological until proven otherwise 2, 3

Signs of Chronicity

• Sentinel skin tag distal to the fissure 2, 3
• Hypertrophied anal papilla at the proximal margin 2, 3
• Fibrosis and visualization of bare internal sphincter muscle at the fissure base 2, 3

Common Pitfalls to Avoid

• Do not perform instrumentation (anoscopy, endoscopy) in the setting of marked pain—this is traumatic and rarely yields diagnostic information 2
• Do not rush to surgery—most fissures can be managed nonsurgically, and surgery carries incontinence risk 6
• Do not use glyceryl trinitrate as first-line topical therapy—calcium channel blockers are superior in efficacy and tolerability 1, 5
• Do not continue failed conservative therapy beyond 2 weeks—escalate to topical pharmacological agents 3, 1