title: Clinical and physiologic effects of biofeedback in outlet obstruction constipation.
abstract: OBJECTIVE
  We report the results of biofeedback (BF) on patients with outlet obstruction defecation (OOC), including those with and without measurable paradoxical puborectalis contractions (PP). Clinical and anorectal physiologic parameters (ARP) were assessed one week before and after a standardized course of BF.
  
  
  METHODS
  Sixty-two consecutive patients (24 men, 38 women; mean age, 48 (standard error of the mean, 2.3) years) were recruited. All had persistent constipation despite six weeks of dietary fiber supplements. Colonic inertia was excluded by transit marker studies. Defecating proctography excluded anatomic abnormalities causing outlet obstruction. Patients underwent four outpatient sessions of biofeedback, each session lasting one hour.
  
  
  RESULTS
  After BF, 56 patients (90.3 percent) were subjectively improved. Frequency of spontaneous bowel movements were significantly increased (P = 0.003). Frequency of laxative-induced (P = 0.004) and enema-induced (P = 0.005) stools were reduced. Anal resting (P = 0.04) and squeeze (P = 0.002) pressures were increased. Number of patients with PP was reduced from 40 to 31 (P = 0.004). Presence of PP did not affect response to BF. There were no differences in ARP between the 56 patients who improved and the 6 who did not. There were no side effects or clinical regressions after a mean follow-up of 14.9 (standard error of the means, 0.9) months.
  
  
  CONCLUSIONS
  BF effectively treated OOC in 90.3 percent, regardless of PP. Anal pressures were increased, and PP was decreased.
authors.affiliation: Department of Colorectal Surgery, Singapore General Hospital.
authors.forename: Y H
authors.initials: YH
authors.lastname: Ho
authors.forename: M
authors.initials: M
authors.lastname: Tan
authors.forename: H S
authors.initials: HS
authors.lastname: Goh
mesh_terms: D001676:Biofeedback, Psychology; D003248:Constipation / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D012007:Rectum / Q000503:physiopathology; D016896:Treatment Outcome