OBJECTIVE: To examine changes in the prevalence and severity of urinary incontinence (UI) and fecal incontinence in morbidly obese women undergoing laparoscopic weight loss surgery. METHODS: In a prospective cohort study, 101 women (aged 20-55 years) with body mass index (BMI) of 40 or more underwent laparoscopic Roux-en-Y gastric bypass and were followed to 6 and 12 months. Presence, severity, and effect of UI were assessed using the Medical, Epidemiological, and Social Aspects of Aging Questionnaire, Urogenital Distress Inventory, and Incontinence Impact Questionnaire. Fecal incontinence was assessed by self-report of anal leakage. RESULTS: Mean BMI decreased from 48.9±7.2 presurgery to 35.3±6.5 at 6 months and 30.2±5.7 at 12 months postsurgery. Prevalence of UI decreased from 66.7% presurgery to 41.0% at 6 months and 37.0% at 12 months (P<.001; 95% confidence interval [CI] for change 18.6-40.0%). Reduction in prevalence of UI was significantly associated with decreases in BMI (P=.01). Among incontinent women who lost 18 or more BMI points, 71% regained urinary continence at 12 months. Medical, Epidemiological, and Social Aspects of Aging Questionnaire urge and stress scores decreased (both P<.001; 95% CI 0.5-1.85 and 2.71-5.34, respectively), as did scores on the Urogenital Distress Inventory (P<.001; 95% CI 8.31-16.21) and Incontinence Impact Questionnaire (P<.001; 95% CI 4.71-14.60), indicating reduction in severity. Prevalence of fecal incontinence (solid or liquid stool) decreased from 19.4% to 9.1% at 6 months and 8.6% at 12 months (P=.018; 95% CI 2.1-19.4%). CONCLUSION: Prevalence of UI and fecal incontinence decreased after bariatric surgery. Magnitude of weight loss was associated with reduction in UI prevalence, strengthening the inference that improvements are attributable to weight loss. © 2007 The American College of Obstetricians and Gynecologists.