What is the management and treatment of an anal fissure?

Management and Treatment of Anal Fissure

Start all anal fissures with conservative management for 2 weeks, then add topical diltiazem (calcium channel blocker) if no improvement, escalate to botulinum toxin injection if topical therapy fails, and reserve surgery only for chronic fissures unresponsive after 8 weeks of non-operative management. 1

Initial Conservative Management (First-Line for All Fissures)

Conservative measures heal approximately 50% of all anal fissures and should be implemented immediately: 1

• Fiber supplementation through diet or supplements to soften stools 1, 2
• Adequate fluid intake to maintain soft stool consistency 1, 2
• Sitz baths to relax the internal anal sphincter 1, 2
• Topical analgesics (lidocaine 5%) for pain control, which reduces reflex sphincter spasm and enhances healing 1, 3
• Stool softeners if dietary changes prove insufficient 2

Pain relief typically occurs within 14 days of starting appropriate treatment, and most acute fissures heal within 10-14 days with conservative management alone. 2

Topical Medical Therapy (Second-Line After 2 Weeks)

If the fissure persists beyond 2 weeks despite conservative management, add topical calcium channel blockers: 1, 2

Topical Diltiazem (Preferred First-Line Topical Agent)

• Diltiazem 2% cream is as effective as glyceryl trinitrate but with significantly fewer side effects 1
• Healing rates of 65-95% with minimal adverse effects 1, 2
• Apply approximately 2 cm (0.7 g) to the anal verge twice daily for 8 weeks 4
• The American College of Gastroenterology recommends calcium channel blockers as first-line topical treatment over nitroglycerin 1

Alternative: Glyceryl Trinitrate (Less Preferred)

• Healing rates of only 25-50%, significantly lower than diltiazem 2
• Headaches occur in up to 84% of patients, limiting compliance 5
• Should not be first choice due to lower effectiveness and higher side effect profile 6

Special Consideration: Infected Fissures

• Add metronidazole cream combined with lidocaine 5% applied 3 times daily when infection or poor genital hygiene is present 3
• This combination shows healing rates of 86% versus 56% with lidocaine alone 3
• Statistically significant pain reduction as early as week 2 (VAS 2.6 vs 3.3, p=0.004) 3

Botulinum Toxin Injection (Third-Line)

If topical treatments fail after appropriate trial, consider botulinum toxin before surgery: 1

• Cure rates of 75-95% with low morbidity 1
• Works by causing temporary sphincter relaxation 1
• Nearly as effective as surgery without significant permanent adverse effects 6, 5
• Transitory episodes of mild fecal incontinence may occur in up to 12% but resolve 6, 5
• Particularly appropriate for patients at risk for developing incontinence 6

Surgical Management (Fourth-Line After 8 Weeks)

Surgery should be considered only for chronic fissures non-responsive after 8 weeks of conservative management: 1, 2

• Lateral internal sphincterotomy (LIS) achieves healing in >95% of cases with recurrence rates of only 1-3% 6, 7
• Remains the gold standard in English-speaking countries and most effective long-term treatment 7
• Risk of permanent fecal incontinence exists, making it controversial—this is why medical management should be exhausted first 6, 7
• Alternative techniques include fissurectomy combined with anoplasty, calibrated sphincterotomy, or sphincteroplasty to reduce incontinence risk 7

Critical Contraindications and Pitfalls

Absolutely Avoid:

• Manual dilatation is strongly contraindicated due to high risk of temporary incontinence (up to 30%) and permanent incontinence (up to 10%) 3, 7
• Surgical treatment should be avoided for acute fissures—surgery is only for chronic fissures after failed medical management 2, 3
• Forcible uncalibrated anal dilatation is no longer recommended 7

Warning Signs Requiring Further Evaluation:

• Atypical fissure location (not posterior midline) requires evaluation for Crohn's disease or inflammatory bowel disease 2
• Signs of chronicity include sentinel tag, hypertrophied papilla, fibrosis, and visualization of bare internal sphincter muscle 2
• Failure to respond after 8 weeks warrants reassessment and specialist referral 2, 3

Pediatric Considerations

The same stepwise approach applies to children with specific modifications: 2

• Most pediatric fissures heal within 10-14 days with conservative management alone 2
• If persistent beyond 2 weeks, add topical calcium channel blockers (diltiazem or nifedipine) with healing rates of 65-95% 2
• Surgery should be avoided in acute pediatric fissures and only considered for chronic fissures non-responsive after 8 weeks 2
• Manual dilatation is strongly discouraged in children due to complication risk 2