Is the enuretic female bladder without instability normal?

Twenty-one females with a history of nocturnal enuresis were found to have stable bladders on cystometric testing. A stable detrusor is defined as one that is capable of contraction but does not develop abnormal contractions on filling inspite of provocative testing by rapid filling, standing, coughing and erect filling. A detailed assessment of 10 measurements revealed abnormalities in 19 of the 21 cases. This result strengthens the theory that for nocturnal enuresis to occur, two abnormalities are necessary: (a) failure of a full bladder to arouse from sleep, and (b) an abnormality of bladder/urethral function. Identifiable causes of nocturnal enuresis included a small functional bladder capacity, outlet obstruction, increased detrusor contractility and low urethral closure pressure.