What are the treatment options for anal fissure?

Treatment Options for Anal Fissure

Conservative management should be the first-line treatment for anal fissures, consisting of fiber supplementation, adequate fluid intake, sitz baths, and topical analgesics, as approximately half of all fissures will heal with these measures alone. 1

Diagnosis and Assessment

Anal fissure presents as a longitudinal tear within the anal canal, extending from the dentate line to the anal verge. Key diagnostic features include:

• Severe pain during and after defecation
• Bright red, scanty bleeding
• Physical examination showing a split in the squamous epithelium at or just inside the anal verge
• Most fissures (90%) occur in the posterior midline 1

Warning Signs Requiring Further Investigation

Atypical features that warrant additional testing (endoscopy, CT scan, MRI, or endoanal ultrasound):

• Lateral or multiple fissures
• Suspicion of inflammatory bowel disease
• Possible anal or colorectal cancer
• Occult perianal sepsis 1

Treatment Algorithm

Step 1: Conservative Management (First-Line)

• Stool softeners:

  • High-fiber diet or fiber supplements
  • Increased fluid intake
  • Bulk-forming laxatives 1

• Pain control measures:

  • Warm sitz baths (reduce sphincter spasm)
  • Topical analgesics
  • Common pain killers if needed 1

• Topical antibiotics: Consider only in cases of poor genital hygiene or reduced therapeutic compliance 1

Step 2: Pharmacological Sphincter Relaxation (If conservative measures fail)

• Topical nitrates (glyceryl trinitrate):

  • Mechanism: Vasodilation, increases blood flow, reduces internal anal sphincter tone
  • Efficacy: 25-50% healing rates
  • Side effects: Headaches (common) 1

• Topical calcium channel blockers (diltiazem, nifedipine):

  • Mechanism: Block L-type calcium channels in smooth muscle cells
  • Efficacy: Similar to nitrates
  • Advantage: Fewer side effects than nitrates 1

• Botulinum toxin injection:

  • Mechanism: Temporary paralysis of anal sphincter (2-3 months)
  • Efficacy: 75-95% cure rates
  • Side effects: Transient mild fecal incontinence 1, 2

Step 3: Surgical Management (For chronic fissures unresponsive to medical therapy)

• Lateral internal sphincterotomy (LIS):
  • Indicated after 8 weeks of failed non-operative management 1
  • Efficacy: >95% healing rate, low recurrence (1-3%) 2
  • Risk: Permanent minor fecal incontinence in a minority of patients 1

Important Considerations and Pitfalls

1. Distinguish between acute and chronic fissures:

   • Acute fissures respond better to conservative treatment
   • Chronic fissures (>6 weeks) often have visible sphincter muscle fibers at the base, sentinel tag, and hypertrophied anal papilla 1, 3

2. Manual anal dilatation is not recommended:

   • Strong recommendation against this practice due to risk of sphincter damage 1

3. Surgical timing:

   • Surgery is not recommended for acute fissures
   • Consider surgery only for chronic fissures unresponsive after 8 weeks of non-operative management 1

4. Medication availability:

   • Appropriate diluted glyceryl trinitrate and topical calcium channel blocker preparations may not be commercially available in some regions 1

5. Pathophysiology awareness:

   • Internal anal sphincter hypertonia and decreased blood flow are key factors in fissure development and persistence
   • Only 25% of patients with anal fissures report constipation 1

By following this stepwise approach to anal fissure treatment, most patients will achieve healing with minimal risk of complications or long-term sequelae.