What is the best management approach for a 2-month-old internal anal fissure?

Management of a 2-Month-Old Internal Anal Fissure

Start with conservative management including fiber supplementation (25-30g daily), adequate fluid intake, warm sitz baths 2-3 times daily, and topical analgesics, as this chronic fissure still has a reasonable chance of healing with medical therapy before considering surgical intervention. 1, 2

Initial Conservative Approach

A 2-month-old fissure is classified as chronic (>8 weeks is the typical cutoff, but symptoms >6 weeks warrant aggressive medical management). However, approximately 40% of chronic fissures still respond to conservative treatment, though this is lower than the 80% healing rate seen in acute fissures. 3

Conservative measures include:

• Fiber supplementation of 25-30g daily to soften stools and minimize anal trauma during defecation 1, 2
• Adequate fluid intake throughout the day to prevent constipation 1, 2
• Warm sitz baths 2-3 times daily to promote internal anal sphincter relaxation 1, 2
• Topical analgesics (lidocaine 5%) for pain control 1

First-Line Pharmacologic Therapy

If conservative measures alone are insufficient after 10-14 days, or if pain is significant, add pharmacologic sphincter relaxation:

Compounded 0.3% nifedipine with 1.5% lidocaine applied three times daily for at least 6 weeks achieves 95% healing rates by reducing internal anal sphincter tone and increasing local blood flow to the ischemic ulcer. 1, 2 Pain relief typically occurs after 14 days of treatment. 2

Alternative option: Compounded 2% diltiazem cream applied to the anal verge twice daily for 8 weeks achieves healing rates of 48-75% without the headache side effects associated with nitroglycerin. 1

Why Not Nitroglycerin First?

Topical nitroglycerin (GTN) shows only 25-50% healing rates and causes headaches in many patients, making it inferior to calcium channel blockers. 4, 1

Second-Line Pharmacologic Therapy

If topical calcium channel blockers fail after 6-8 weeks, consider botulinum toxin injection into the internal anal sphincter, which demonstrates 75-95% cure rates with low morbidity. 4, 1 The optimal injection location (internal vs. external sphincter) remains somewhat controversial, but this represents an excellent option before proceeding to surgery. 4

Surgical Intervention

Lateral internal sphincterotomy (LIS) should only be considered after documented failure of at least 6-8 weeks of comprehensive conservative management including fiber, fluids, sitz baths, and topical pharmacologic therapy. 1, 5

LIS remains the gold standard with:

• >95% healing rates 1, 6, 7
• 1-3% recurrence rates 1, 6
• Small risk of minor permanent incontinence (significantly lower than the 10-30% permanent incontinence rate with manual anal dilatation) 1, 2

Critical Pitfalls to Avoid

• Never use manual anal dilatation - it is absolutely contraindicated due to unacceptably high permanent incontinence rates of 10-30%. 1, 2, 5
• Do not use hydrocortisone beyond 7 days due to risk of perianal skin thinning and atrophy, which can worsen the fissure. 1, 2
• Do not rush to surgery for a 2-month-old fissure - give medical therapy a full 6-8 week trial first unless pain is absolutely intractable. 1, 5

Red Flags Requiring Further Workup

If the fissure is located off the midline (lateral or multiple fissures), urgently evaluate for serious underlying conditions such as Crohn's disease, inflammatory bowel disease, HIV, syphilis, herpes, anorectal cancer, or tuberculosis, as typical fissures occur in the posterior midline in 90% of cases. 1

Practical Algorithm

1. Weeks 0-2: Conservative management (fiber, fluids, sitz baths, topical analgesics)
2. Weeks 2-8: Add topical 0.3% nifedipine with 1.5% lidocaine three times daily (or 2% diltiazem twice daily)
3. Week 8: If failed, consider botulinum toxin injection
4. Week 12-16: If still failed, refer for lateral internal sphincterotomy

Given that healing rates decrease from 100% in patients with symptoms <1 month to 33.3% in patients with symptoms >6 months, your 2-month-old fissure is at a critical juncture where aggressive medical management is warranted but still has reasonable success rates. 3