Randomized prospective controlled trial of lateral internal sphincterotomy versus injection of botulinum toxin for the treatment of idiopathic fissure in ano

Background: Chronic anal fissure is a significant cause of morbidity. Internal sphincterotomy has long been the operative treatment of choice. Concerns remain, however, on its effects on continence. Botulinum toxin has been used as an agent for chemical sphincterotomy, causing temporary alleviation of sphincter spasm and allowing the fissure to heal. The aim of the present study was to compare the results of sphincterotomy to botulinum toxin. Methods: The study was designed as a randomized controlled trial. All adult patients over the age of 18 with chronic idiopathic fissure in ano who had failed conservative treatment were included in the trial. Patients were randomized to receive either Botox or sphincterotomy. Pain, healing of fissure and continence scores were the outcomes assessed. Results: A total of 38 patients were studied. Seventeen patients were randomized to receive Botox and 21, sphincterotomy. Patients in the Botox group were found to have significantly higher 2-week pain scores and reoperation rates, and poor healing. Continence scores were not significantly different in the two groups. Conclusion: Sphincterotomy gives better results than Botox in the treatment of fissure. Botox, however, is safe with no complications and no detriment to continence and could be used in certain situations.