Changes in the concept of neural organization for micturition and the use of high flow gas cystometers have altered the performance of clinical cystometry and test interpretation. Detrusor reflex activation procedures in carbon dioxide cystometry include rapid bladder distension, change in postural states, use of bethanechol, urethral and anal distension, and sleep. Sleep cystometry requires the use of electroencephalography. These procedures have permitted specific delineation of the syndrome of detrusor reflex instability. Test interpretation is based upon detection of the presence of detrusor reflex instability or end organ denervation.