Biofeedback re-education of faecal continence in children

The purpose of this prospective study was to see if pretreatment anorectal motility can predict successful correction of faecal incontinence with biofeedback. Forty-seven consecutive children, aged 5 to 18 years, were treated. They had been treated for idiopathic constipation with faecal impaction, but had remained incontinent (n=15), had been operated for congenital anorectal malformations of high (n=19) or low (n=2) type, or had a number of organic congenital pelvic abnormalities (n=11). This consecutive series represents our entire experience with biofeedback for faecal incontinence, in the period from January 1 1983 to December 31 1989. In each patient, at the first session, anorectal manometry was performed. Resting pressures in the rectum, upper anal canal and lower anal canal were measured. The threshold of rectal sensation during distension, the maximal pressure during voluntary sphincteric contraction and the time to half decrease of sphineteric pressure because of muscular fatigue were also noted. The patient was then asked to make a voluntary sphincteric contraction, while the rectum was being distended with the volume at threshold for rectal sensation. In subsequent sessions, the rectum was also distended but without warning the patient, who was congratulated when he or she contracted the sphincter immediately after onset of rectal distension. Full continence was the criterion used to classify re-education as a success. Improvement or no change in continence was considered as failure of the treatment. Three parameters only improved after treatment: the threshold for rectal sensation which decreased (P<0.05), the maximal peak of voluntary contraction which increased (P<0.001), and the duration of this contraction which was prolonged (P<0.05). Patients who were to recover had, before treatment, lower threshold of rectal sensation (P<0.01), higher maximum voluntary contraction of the anal sphincter (P<0.05), and tended to have a higher resting tone in the anal canal (P=0.07). In addition, after biofeedback treatment, the decrease of threshold for rectal sensation (P<0.05), increase of maximal voluntary contraction (P<0.005) and maintained contractions (P<0.05) were more important in patients who became continent than in those who remained incontinent. Fifty per cent of the patients were cured from faecal incontinence by biofeed-back re-education. Success was much higher in patients initially seen for constipation and faecal incontinence (92%) than in the other patients (35%) (P<0.01). Patients with constipation had higher pressures in the upper anal canal, in addition to better voluntary contraction, and lower threshold of rectal sensation, both before and after treatment, than patients with other disorders. It is concluded that there is a correlation between cure from faecal incontinence and improvement in anorectal sensitive and dynamic parameters but that this may largely be due to the underlying disorder.