Randomised controlled trial of biofeedback training in persistent encopresis with anismus

Abstract

Background-Paradoxical external anal sphincter contraction during attempted defecation (anismus) is thought to be an important contributor to chronic faecal retention and encopresis in children. Biofeedback training can be used to teach children to abolish this abnormal contraction. Methods-A randomised controlled trial in medical treatment resistant and/or treatment dependent children with anismus using surface electromyographic (EMG) biofeedback training to determine whether such training produces sustained faecal continence. Up to four sessions of biofeedback training were conducted at weekly intervals for each patient. Anorectal manometry was performed before randomisation and six months later. Parents of patients completed the "child behaviour checklist" (CBCL) before randomisation and at follow up. Results-Sixty eight children underwent anorectal manometry and EMG. Of these, 29 had anismus (ages 4-14 years) and were randomised to either EMG biofeedback training and conventional medical treatment (BFT) (n = 14) or to conventional medical treatment alone (n = 15). All but one child were able to learn relaxation of the external anal sphincter on attempted defecation. At six months' follow up, laxative free remission had been sustained in two of 14 patients in the BFT group and in two of 15 controls (95% confidence interval (CI) on diVerence, −24% to 26%). Remission or improvement occurred in four of 14 patients in the BFT group and six of 15 controls (95% CI on diVerence, −46% to 23%). Of subjects available for repeat anorectal manometry and EMG at six months, six of 13 in the BFT group still demonstrated anismus v 11 of 13 controls (95% CI on diVerence, −75% to −1%). Of the four patients in full remission at six months, only one (in the BFT group) did not exhibit anismus. Rectal hyposensitivity was not associated with remission or improvement in either of the groups. Mean CBCL total behaviour problem scores were not significantly diVerent between the BFT and control groups, but there was a significant improvement in CBCL school scale scores in the BFT group, and this improvement was significantly greater than that seen in the control group.Conclusions-The result of this study, together with those reported in other controlled trials, argues against using biofeedback training in children with encopresis.

Dynamic MR assessment of the anorectal angle and puborectalis muscle in pediatric patients with anismus: Technique and feasibility

“…The preliminary results of the present study indicate that any radiological evidence of paradoxical contraction of the pelvic-floor muscle and acute angulation of the anorectal angle during straining identified by dynamic MRI in the supine position would suffice to differentiate normal from abnormal defecation dynamics. It is noteworthy that ARM and anorectal endosonography also require the patient to adopt a leftlateral position (1,18,22).…”

Biofeedback Treatment for Functional Anorectal Disorders: A Comprehensive Efficacy Review

“…This normalization of physiological activity, however, was unrelated to clinical outcome. Nolan et al (1998) compared standard medical care alone or with the addition of 3-4 session coordination biofeedback in 29 children with PFD between the ages of 4 and 14. There were no significant differences in outcomes between the two groups; 4 out of 14 BF children and 6 out of 15 controls improved.…”

Evaluation of the effectiveness of biofeedback therapy for functional constipation in children

“…The third randomized trial was conducted by Nolan et al (33) and included only patients with an abnormal defecation track, with the results showing no significant advantage of EMG biofeedback over conventional methods. However, the studies conducted by Wald et al (32) and Nolan et al (33) did not include a sufficient number of patients for statistical analysis. Moreover, there were different causes of constipation in the groups.…”