Mild and Severe Anal Incontinence after Lateral Internal Sphincterotomy: Risk Factors, Postoperative Anatomical Findings and Quality of Life

Aim: This study aims to evaluate the risk factors for incontinence after lateral internal sphincterotomy (LIS) and assess quality of life in different levels of incontinence. Methods: All consecutive patients (n = 253) with chronic anal fissure who underwent LIS between 2003 and 2006 were retrospectively reviewed. All patients were questioned for possible anal incontinence according to the Wexner Incontinence Score (WIS). Demographics, vaginal delivery history, additional procedures and surgeon’s experience were evaluated as risk factors. Endoanal ultrasound (EUS) was performed in incontinent patients to assess the thickness of the remaining internal sphincter and to evaluate any injury in the external sphincter. Quality of life was questioned with SF-36. Results: Twenty-eight (11.7%) patients suffered from incontinence (mean WIS = 3.6 ± 2.5). The search for a risk factor was unsuccessful when continent and incontinent groups were compared. In subgroup analyses, patients were found to be suffering from mild (WIS 5, n = 9) incontinence. Vaginal delivery history was found more often in the severely incontinent subgroup than in the continent group (p < 0.05). Also, vaginal delivery history and the additional procedures were more frequently observed in the severely incontinent subgroup than in the mildly incontinent subgroup. EUS did not find any external sphincter injury in these cases. WIS had negative correlations with the physical and mental component scores of SF-36. Conclusion: In our opinion, the threat for incontinence is unpredictable; however, vaginal delivery history may increase the risk of severe incontinence.