Abstract: A preferred embodiment of the present invention is a system composed of several devices that function together to selectively, on demand, control the flow of urine through the urethra. A valve also permits catheter-based elective or emergency instrumentation of the upper urinary tract without removal of the valve from the urethra. One aspect of the present invention is a body-implanted, coordinating system of devices for managing urine flow from a patient's urinary bladder through the urethra to the external environment primarily to prevent urinary incontinence with its sequelae. Another aspect of the present invention is a method or process for managing urine flow through a patient's urethra to prevent untimely and unintended incontinence of urine. The function and specific design of the valve assembly disclosed herein permits catheter-based elective or emergency instrumentation of the upper urinary tract without removal of the valve from the urethra.