Background Bladder, bowel, and sexual symptoms are common among persons with multiple sclerosis (MS). We aimed to investigate the frequency and severity of bladder, bowel, and sexual symptoms, the relationships between these symptoms, satisfaction with treatment of these symptoms, and factors associated with symptom severity and treatment satisfaction. Methods In the fall 2010, we surveyed participants in the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry regarding the severity of being bothered by bladder, bowel, and sexual symptoms, their satisfaction of health providers’ inquiry and treatment with these symptoms, and whether their quality of life (QOL) had changed with the treatment. Logistic regression was used to evaluate demographic and clinical factors associated with each outcome. Results Of 9341 respondents included in the study, 7720 (77.4%) were female and their mean (SD) age was 50.3 (10.5) years. Ninety-one percent of participants were mildly, moderately or severely bothered by bladder, bowel or sexual symptoms. Severity of disability (measured using the Patient Determined Disease Steps), having a relapse in the last 6 months, and catheter use were consistently associated with being bothered (versus not bothered) by each of the three symptoms. Among respondents, 5764 (62.1%) reported that their MS health providers asked about bladder problems, 4523 (51.1%) about bowel problems, and 1890 (20.6%) about sexual problems. At most one-third of participants were completely satisfied with treatment for any of the symptoms. For those who reported how their QOL changed with treatment, 23.0% reported their QOL being better. Conclusion Bladder, bowel, and sexual problems remain common among persons with MS, and treatment satisfaction is low. Health care providers should consider systematically asking about these symptoms in clinical practice. Greater efforts could be devoted to developing novel, effective therapies to manage these symptoms and thereby improve QOL.