RESUMEN
Background: Standard treatment for Chronic Anal Fissure (CAF) is unilateral Internal Sphincterotomy (UIS). Still there is recurrence and the risk of of incontinence. Bilateral Internal Sphincterotomy (BIS) as a treatment for CAF has not been adequately evaluated. Methods: A prospective randomized controlled trial of UIS at 3 o clock compared with BIS at 3 and 9 ‘O’ clocks. The outcome variables were : post operative pain, recurrence and incontinence. Result: There was 104 and 107 cases in UIS and BIS group respectively with similar age and sex. There were 12 recurrences in UIS and only one in the BIS group (p< 0.001) with no change in the continence. BIS group had less pain (p<0.001). Conclusion: BIS for CAF resulted in less postoperative pain, lower recurrence with no increase in the incontinence. However, further study is required with pre and post operative anal manometry.