ABSTRACT
INTRODUCTION The lower urinary tract comprises the bladder, urethra and striated sphincter, which act as a single functional unit under nervous control. The bladder has two principal functions; first, to be a secure lowpressure storage reservoir for the entire urine output from the kidneys and, second, to contract efficiently and empty at socially convenient times. The normal person voids on average about 300 ml completely in about 40 seconds six times a day with no leakage and little sensation of bladder filling in between. However, if these functions are ever compromised, as, for example, in patients presenting with symptoms such as incontinence, urgency, frequency or obstructed voiding, it is important that we are able to assess the operation of the lower urinary tract objectively during both the storage and voiding phases.
