title: A randomized controlled trial of anorectal biofeedback for constipation.
abstract: OBJECTIVE
  The purposes of this study were: (1) to examine the efficacy of anorectal biofeedback (AB) for constipation compared to a biofeedback control (BC) treatment and (2) to examine the extent to which self-reported childhood sexual/physical abuse predicted biofeedback outcome.
  
  
  METHODS
  Twenty-one patients with pelvic floor dyssynergia were randomized to either (1) an AB arm, where patients learned to isolate the anal sphincter using an electromyography probe, or (2) a BC arm that controlled for the nonspecific effects of biofeedback, where patients learned to relax trapezius or temporalis muscles with EMG feedback. Both treatments were delivered by registered nurses for six sessions. Prior to randomization and post-treatment, patients completed the validated Constipation Severity Instrument and two measures of quality of life (QOL), the Irritable Bowel Syndrome-QOL, and the SF-36. Generalized estimating equations examined the within-group and between-group differences over time.
  
  
  RESULTS
  Pre- and post-treatment data were obtained for six AB and nine BC patients. AB patients' overall constipation severity scores decreased by 35.5% (vs. 15.3%), and their obstructive defecation symptom scores decreased by 37.9% (vs. 19.7%) compared to BC. A similar pattern was shown on the IBS-QOL. On the SF-36 Mental Health Composite (MCS), AB scores improved 28.0% compared to BC scores, which worsened 12.7%. Those without (vs. with) a childhood sexual/physical abuse history showed improvement on the MCS post-biofeedback.
  
  
  CONCLUSIONS
  While our sample was statistically underpowered, AB produced clinical improvements in constipation severity and QOL.
authors.affiliation: Department of Psychology, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada. Stacey.hart@psych.ryerson.ca
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Hart
authors.forename: Janet Waimin
authors.initials: JW
authors.lastname: Lee
authors.forename: Julia
authors.initials: J
authors.lastname: Berian
authors.forename: Taryn R
authors.initials: TR
authors.lastname: Patterson
authors.forename: Amanda
authors.initials: A
authors.lastname: Del Rosario
authors.forename: Madhulika G
authors.initials: MG
authors.lastname: Varma
mesh_terms: D001003:Anal Canal / Q000503:physiopathology*; D001676:Biofeedback, Psychology / Q000379:methods*; D002648:Child; D002650:Child Abuse, Sexual; D003248:Constipation / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011788:Quality of Life; D012007:Rectum / Q000503:physiopathology*; D016896:Treatment Outcome