A Comparison of Injections of Botulinum Toxin and Topical Nitroglycerin Ointment for the Treatment of Chronic Anal Fissure

Anal fissure, a split in the skin of the distal anal canal, is a common problem that causes substantial morbidity in people who are otherwise healthy. The incidence of anal fissure is similar in men and women. 1 , 2 The majority of fissures occur in the posterior midline of the anal canal; multiple fissures or lateral fissures may have other causes, such as Crohn's disease, ulcerative colitis, tuberculosis, infection with the human immunodeficiency virus (HIV), or syphilis. 1 – 3 Spasm of the anal sphincter has been noted in association with anal fissure, 4 , 5 and for many years treatment has focused on alleviating . . .