Botox for the treatment of chronic anal fissure: A randomized controlled trial

Chronic anal fissure is a common condition. An acute tear at the anal verge, if fails to heal within six weeks, leads to chronicity; characterized by increased anal tone, epithelial breach and fibrosis at the base of the fissure. The aim of the treatment, therefore, is to reduce the anal tone and increase the blood supply for healing. Traditionally the treatment has been surgical i.e. lateral internal sphincterotomy under anaesthesia. Apart from surgery, several pharmacological options, aimed at reducing anal tone, have also been used with variable success rates. Out of those Glyceryl Trinitrate (GTN), Diltiazem and Botulinum toxin (Botox) have been studied with successful outcomes. The current research regarding comparison of GTN and Botox is limited, and the RCTs conducted so far have either short follow up duration or small sample sizes. Moreover no study has been conducted locally to compare the efficacy of the two drugs. The hypothesis of the study is that Botox injection leads to healing of the fissure more effectively than GTN.