RESUMO
Anal fissure is a common disorder which may cause symptoms at any age. Internal anal sphincterotomy is the gold standard surgical treatment which lowers the resting anal pressure and effectively heals the majority of fissures. However the post operative period may be marked by surgical risks, complications and late incidence of incontinence that is some times permanent. These complications has led to a search for alternative therapies for the treatment of chronic anal fissure. Chemical sphincterotomy has been tried using a variety of novel agents including topical glyceryl trinitrate (GTN), calcium channel blockers such as nifedipine or diltiazem and botulinum toxin. Some of these agents were found to be effective in healing chronic anal fissure with negligible side effects and are now considered as first line treatment for chronic anal fissure.