Treatment of Anal Fissure
Non-operative management with dietary modifications and topical calcium channel blockers should be the first-line treatment for anal fissures, with botulinum toxin injection reserved for failures after 8 weeks of conservative therapy. 1, 2, 3
Initial Conservative Management (First 2 Weeks)
Start all patients with conservative measures, which heal approximately 50% of anal fissures within 10-14 days: 1, 3
- Stool softeners: Increase oral fluid intake, high-fiber diet or fiber supplements, and bulk-forming laxatives 1
- Warm sitz baths to promote sphincter relaxation and increase local blood flow 1
- Topical analgesics (lidocaine) for pain control, which reduces reflex sphincter spasm and enhances healing 1, 3
Topical Pharmacological Treatment (If No Improvement After 2 Weeks)
Topical calcium channel blockers (diltiazem or nifedipine) are superior to nitroglycerin as first-line topical agents: 1, 2, 3
- Calcium channel blockers achieve healing rates of 65-95% with minimal side effects 2, 3
- Nitroglycerin ointment is second-line with lower healing rates of 25-50% and significant headache side effects (up to 17% discontinuation rate) 2, 3, 4
- The American College of Gastroenterology specifically recommends calcium channel blockers over nitroglycerin due to comparable efficacy but significantly fewer adverse effects 1, 3
Botulinum Toxin Injection (After 8 Weeks of Failed Conservative/Topical Therapy)
Botulinum toxin injection should be considered when topical treatments fail, achieving cure rates of 75-95% without risk of permanent incontinence: 2, 3
- The American Gastroenterological Association recommends botulinum toxin as the preferred non-surgical option for chronic fissures that fail conservative management 2
- Botulinum toxin is superior to nitroglycerin (96% vs 60% healing rate) with no adverse effects compared to headaches in nitroglycerin users 5
- It causes temporary sphincter paresis for approximately 3 months, allowing reversible sphincter relaxation without permanent damage 2
- Particularly indicated for patients with compromised sphincter function or risk factors for incontinence 2
Surgical Treatment (Reserved for Refractory Cases)
Lateral internal sphincterotomy remains the gold standard surgical treatment with >95% healing rates but carries risk of permanent fecal incontinence: 6, 7
- Surgery should only be considered after failure of 8 weeks of non-operative management 3
- Sphincterotomy provides faster pain relief (70% at 2 weeks) and earlier healing (85% at 4 weeks) compared to medical therapy 8
- The risk of permanent incontinence makes surgery controversial and should be reserved for severe disabling pain or chronic/complicated fissures 6, 7
Critical Pitfalls to Avoid
- Never use manual dilatation due to high risk of temporary and permanent incontinence 1, 3
- Do not rush to surgery for recurrent fissures—repeat the conservative approach first 2
- Do not use botulinum toxin as first-line treatment—exhaust conservative and topical therapies first 2
- Evaluate atypical fissures (lateral location, multiple, or non-healing) for inflammatory bowel disease, sexually transmitted diseases, anorectal cancer, or tuberculosis 1