RESUMO
Two experiments compared the effects of biofeedback training to behavior modification in the treatment of 33 children aged 5 to 16 who had fecal incontinence secondary to myelomeningocele. Biofeedback involved providing visual feedback and rewards for successively stronger sphincter contractions during training sessions and requiring 50 sphincter contraction exercises daily. Behavior modification involved attempting to defecate immediately after the evening meal each day, receiving a reward for defecating in the toilet without an enema or suppository, and receiving an enema if unsuccessful for two consecutive days. In experiment I, eight children were offered biofeedback alone in an attempt to replicate previous studies. Biofeedback alone was found insufficient; addition of behavior modification was necessary. Experiment II systematically investigated the relative contribution of these two treatments. Overall, patients who received only behavior modification for three months showed as much clinical improvement as patients who received behavior modification plus biofeedback. This suggests that previous reports, because they have not controlled for nonspecific treatment effects, have overestimated the value of biofeedback in this population. However, a subgroup of patients (27%) were identified for whom biofeedback provided additional, specific benefit. These were children who had spinal cord lesions below L-2 and who initially had two or more bowel movements daily. The combination of behavior modification and biofeedback resulted in a greater than 50% reduction in the frequency of incontinence for 64% of patients, and results were well maintained at follow-up one year later.