Intra-sphincteric injection of botulinum toxin seems to be a reliable option causing temporary alleviation of sphincter spasm and allowing the fissure to heal. study is to compare the outcome of surgical sphincterotomy and botulinum toxin injection treatments in patients with uncomplicated chronic anal fissure.

consecutive patients with uncomplicated chronic anal fissure who had failed conservative treatment were randomized to receive either intra-sphincteric injection of botulinum toxin (BT) or lateral internal sphincterotomy (LIS). Postoperative pain relief, healing of fissure, continence scores and fissure relapse during 18 weeks of follow up was the outcomes assessed.

Inclusion Criteria:

• The diagnosis of chronic anal fissure was based on evidence of circumscribed ulcer at anal canal with indurations at the edges and exposure of the horizontal fibers of the internal anal sphincter at its floor.

Exclusion Criteria:

• Anal fissure that had been operated on before, complicated fissure with cicatricial deformation, large sentinel pile, associated hemorrhoids, suspected inflammatory bowel disease, or malignancy.

This trial included consecutive adult patients presenting with symptomatic chronic anal fissure in which conservative treatment had failed.