<b>Introduction:</b> Anal fissure is a common benign anal condition. The gold standard treatment is lateral internal sphincterotomy (LIS), and this procedure carries a risk of incontinence. </br></br> <b> Aim:</b> The aim of this study is to determine the long-term risk of fecal incontinence after LIS. </br></br> <b> Method:</b> All patients who had LIS for chronic anal fissure between the years 2004-2010 were interviewed by phone and assessed for sphincter function (incontinence) using Wexner fecal incontinence score (WIS). </br></br> <b>Results:</b> Fifty-nine patients (34 females, 57.6%) with a mean follow-up duration of 10.6 years (range 8-15 years) were interviewed. Twelve patients (20.3%) had a WIS score of one or more. The majority of the patients noticed a change in sphincter function years after the operation. There was no association between vaginal delivery and the WIS score. </br></br> <b>Conclusion:</b> The long-term risk of abnormal sphincter function after LIS appears to be higher than expected, especially in the presence of multiple vaginal deliveries or systemic diseases such as diabetes mellitus. A larger prospective study is required to establish a correct risk of incontinence in the long term.
Keywords: anal fissure; incontinence; sphincterotomy.