Repeat botulin toxin injections in anal fissure: in patients with relapse and after insufficient effect of first treatment.

Botulin toxin (BoTx) injections are an alternative treatment for uncomplicated anal fissures. Until recently, surgical management has been advocated for therapeutic failure of BoTx and recurrent fissures. In 20 patients with recurring anal fissure we examined the remission rate following a second course of botulin treatment. The dose was identical to the first treatment (5 units Botox). In group 2, 30 patients with therapeutic failure were treated with a higher dose of botulin toxin (10 units). In our patients with recurring fissure, 19 of 20 were pain-free within a week (95%). After three months, 14 patients (70%) had healed fissures. In group 2, 22 of 30 patients (73%) became pain-free within the first week following the second course of treatment. Two patients (7%) suffered from transient mild incontinence. Nineteen patients (63%) showed healed fissures three months following the second BoTx treatment. BoTx remains an effective treatment in recurring anal fissure as well as in patients with therapeutic failure of prior BoTx injections.