What is the initial treatment for an anal fissure?

Initial Treatment for Anal Fissure

The initial treatment for anal fissure should be conservative management, which includes fiber supplementation, adequate fluid intake, sitz baths, and topical analgesics. 1, 2

Conservative Management (First-Line Treatment)

• About 50% of all anal fissures heal with conservative care within 10-14 days 1, 2
• Conservative management consists of:
  • Fiber supplementation to soften stools and prevent constipation 1, 2
  • Ensuring adequate fluid intake 2
  • Warm sitz baths to relax the internal anal sphincter 2
  • Topical analgesics (such as lidocaine) for pain control 2

When to Consider Additional Treatments

• If the fissure persists beyond 2 weeks despite conservative management, or if pain is severe, additional treatments should be considered 2
• Pharmacological options include:
  • Topical calcium channel blockers (diltiazem or nifedipine) with healing rates of 65-95% 2
  • Glyceryl trinitrate (GTN) ointment with healing rates of 25-50%, though headaches are a common side effect 1, 2
  • Botulinum toxin injection with high cure rates (75-95%) and low morbidity 1, 2

Surgical Management

• Lateral internal sphincterotomy (LIS) is the gold standard surgical procedure for chronic anal fissures that don't respond to conservative and pharmacological treatments 1, 2
• Surgery should only be considered for:
  • Chronic fissures not responsive after 8 weeks of non-operative management 2
  • Acute fissures with severe pain that is unmanageable with conservative care 1, 2
• Manual dilatation is strongly discouraged due to high risk of incontinence 2

Important Diagnostic Considerations

• Most anal fissures occur in the mid-line, usually posteriorly 1
• Atypical fissures (those not in the midline) require evaluation for underlying conditions such as Crohn's disease, HIV/AIDS, ulcerative colitis, tuberculosis, syphilis, or cancer 1, 2
• Signs of chronicity include sentinel tag, hypertrophied papilla, fibrosis, and visualization of bare internal sphincter muscle 1, 2

Treatment Algorithm

1. Start with conservative management for all acute anal fissures 1, 2
2. If no improvement after 2 weeks or if pain is severe:
   • Add topical calcium channel blockers or glyceryl trinitrate 2
   • Consider botulinum toxin injection if topical treatments fail 1, 2
3. If pharmacological treatments fail after 8 weeks, consider lateral internal sphincterotomy 2

Common Pitfalls and Caveats

• Instrumentation of the anal canal during examination should be avoided in the setting of marked pain or tenderness as it is traumatic to the patient 1
• Glyceryl trinitrate, while effective, can cause headaches in a significant number of patients, potentially limiting compliance 2, 3
• The optimal location for botulinum toxin injection (internal vs. external sphincter) remains controversial 1
• While lateral internal sphincterotomy is highly effective, there is a risk of permanent minor sphincter impairment 1, 4