title: The utility of conditioning sequences in barostat protocols for the measurement of rectal compliance.
abstract: OBJECTIVE
  A barostat can be used to measure rectal sensitivity, compliance and elastance all of which are potentially important physiological parameters in the pathophysiology of faecal incontinence. Current practice recommends a conditioning distension sequence be performed prior to index distensions. We questioned the validity of this by comparing values for rectal compliance during sequential conditioning (CD) and index (ID) distensions in physiologically normal subjects.
  
  
  METHODS
  Ten subjects (five men, mean age 55.2 years) with normal anal canal manometry, anorectal sensitivity and balloon distension thresholds were studied. After determining the minimum distension pressure, subjects underwent sequential isobaric distensions: CD 4 mmHg distensions every 45 s and ID 4 mmHg every 2 min, both to a maximum of 24 mmHg or patient tolerance. Compliance values from both sequences were calculated by measuring the maximum slope of pressure-volume curves. A paired t-test was performed to compare any differences between sequences.
  
  
  RESULTS
  Mean rectal compliance were 11.4 ml/mmHg (SD 5.8 ml/mmHg) and 10.9 ml/mmHg (SD 5.7 ml/mmHg) in the CD and ID, respectively, with no statistical difference noted between distensions (P = 0.78).
  
  
  CONCLUSIONS
  Rectal compliance can be measured with a single distension protocol without the need for an initial conditioning distension. Conditioning the rectum adds additional complexity to barostat protocols and is not necessary.
authors: Department of Gastroenterology and Nutrition, University College Hospital, London, UK. adeelahmadbajwa@hotmail.com
authors: A
authors: A
authors: Bajwa
authors: K
authors: K
authors: Thiruppathy
authors: A
authors: A
authors: Emmanuel
mesh_terms: D001003:Anal Canal / Q000502:physiology*; D003187:Compliance / Q000502:physiology*; D003938:Diagnostic Techniques, Digestive System; D004106:Dilatation / Q000379:methods; D004548:Elasticity / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D011312:Pressure; D012002:Rectal Diseases / Q000175:diagnosis; D012007:Rectum / Q000502:physiology*