title: Determinants of fecal continence in healthy, continent subjects: a comprehensive analysis by anal manometry, rectal barostat and a stool substitute retention test.
abstract: OBJECTIVE
  This study aimed to identify anal sphincter and rectal factors that determine anorectal filling sensations and continence during rectal filling in health.
  
  
  METHODS
  Measurements of anorectal physiology were collected from 42 continent healthy subjects participating in a prospective trial. Rectal function and capacity were assessed by barostat. Anal sphincter functions were assessed by manometry. A validated stool substitute retention test was performed in which a viscous suspension was infused into the rectum at 60 ml/min to 1,500 ml. Multivariate regression was applied to identify physiologic factors that determine anorectal sensation and continence during rectal filling.
  
  
  RESULTS
  The volume at which first awareness of rectal filling occurred associated with age (p < 0.03), rectal capacity (p < 0.06) and anal resting pressure (p < 0.003); urgency associated with rectal capacity (p < 0.0007), anal resting (p < 0.04) and squeeze pressure (p < 0.02); volume at first incontinence with rectal capacity (p < 0.0001) and squeeze pressure (p < 0.04) and the maximum volume retained were closely correlated with rectal capacity only (p < 0.0001).
  
  
  CONCLUSIONS
  Anorectal filling sensations and continence in health require a rectal reservoir of adequate capacity and effective voluntary anal sphincter function. Complementary associations between continence, motor and sensory function indicate the presence of an adaptive mechanism that enables timely, appropriate responses to events that threaten fecal continence.
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland. mark.fox@nottingham.ac.uk
authors.forename: Mark
authors.initials: M
authors.lastname: Fox
authors.forename: Miriam
authors.initials: M
authors.lastname: Thumshirn
authors.forename: Heiko
authors.initials: H
authors.lastname: Frühauf
authors.forename: Michael
authors.initials: M
authors.lastname: Fried
authors.forename: Werner
authors.initials: W
authors.lastname: Schwizer
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000502:physiology*; D005242:Fecal Incontinence / Q000503:physiopathology; D005243:Feces; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011312:Pressure; D011446:Prospective Studies; D012007:Rectum / Q000502:physiology*; D012677:Sensation / Q000502:physiology*; D055815:Young Adult