Bell and Pad Bladder Training

Description of the Strategy

The problem of nocturnal enuresis or bed-wetting has been written about since ancient times, dating back to the Egyptian papyrus papers in 1550 B.C. This disorder has led to a number of attempts to correct the problem with treatments ranging from medicinal concoctions involving swamp root and juniper berries to using early “medical devices” that included attaching a frog to the waist of the boy who dared to wet his sleeping area. The mystery of why a child would wet in bed has also activated the process of scientific investigation and subsequently spawned as many as 80 years of systematic investigation to identify the causes of bed-wetting and how to eliminate the problem (the incidence of enuresis is twice as common in males up to puberty). Although much science has yet [Page 747]to be done regarding the etiology of bed-wetting and the mechanisms of action that account for effective interventions, psychology as a science has identified a proven treatment: bell and pad bladder training, or the urine alarm.

Perhaps the most widely investigated method to treating bed-wetting is the method of bell and pad bladder training. This method was initially described in the professional literature in 1938 by Mowrer and Mowrer in their practical efforts to deal with the offensive smell of urine in an orphanage for boys, many of which had a problem with wetting their beds. Being early pioneers in learning theory, they approached the problem from the perspective that the boys had failed to learn how to achieve a dry bed and must be taught how to do so. What they basically devised was a method to provide immediate feedback, in the form of punishment, as the wetting accident occurred. Their final design included a moisture-sensitive pad placed on the child's bed that was connected to an alarm box. Once the urine contacted the pad, a circuit was completed in the alarm box and a rather loud auditory stimulus would be activated. The alarm was loud enough to rouse the bed wetter from sleep and eventually interrupt the wetting episode. The Mowrers discovered that over multiple weeks of providing this immediate feedback to the child who wet the bed, the child would eventually remain dry for the entire sleeping period or wake up to visit the toilet. This basic design in the bell and pad method has varied little in the last 50 years other than including body-worn devices (that are considerably smaller) as opposed to the pad.

The bell and pad method (also referred to as urine alarm treatment or conditioning treatment) has proven to be an effective treatment for simple bed-wetting. However, the exact mechanisms that control what is actually occurring in the sleeping bed wetter as he or she progresses to complete remission of the wetting is still not established. Mowrer originally proposed that the change in the child's bed-wetting behavior could best be accounted for through a respondent-conditioning paradigm. The release of urine onto the pad (UCS) would activate the alarm, which would in turn trigger a startle response in the child in the form of a bladder sphincter contraction (UCR), disrupting urination. As treatment progressed and included multiple pairings of the act of urination (UCS) with the alarm (CS), it was thought that all internal bodily sensations in the act of urinating became the signal (CS) that would elicit the bladder sphincter contraction (CR) that would prevent wetting the bed. This was a theoretical explanation that appeared to account for the outcome of this treatment. Unfortunately, Mowrer's respondent conditioning explanation failed to explain why the bladder sphincter contraction did not extinguish when the alarm was withdrawn following successful treatment.

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