Manometric study of the voluntary inhibition action in normal volunteers.
OBJECTIVE
A voluntary inhibition action whereby a voluntary squeeze of the external sphincter causes reflex relaxation of the rectum has been previously proposed but not proven. Such a reflex would enable the subject to defer defecation to a socially acceptable time. The purpose of this study was to determine whether or not such a reflex exists.


METHODS
We measured rectal compliance with and without a voluntary squeeze using a specially designed balloon catheter in nine subjects.


RESULTS
When corrected for increased intra-abdominal pressure caused by inadvertent Valsalva's maneuver during voluntary squeezing, there was a significant increase in rectal compliance during voluntary contraction of the external sphincter (P < 0.01).


CONCLUSIONS
This lends support to the proposed existence of the voluntary inhibition action.
Levien
D
D
Department of Surgery, Episcopal Hospital, Philadelphia, Pennsylvania 19125.
Clark
S B
SB
Rosenthal
W
W
Gross
E
E
D000328:Adult; D001003:Anal Canal / Q000502:physiology*; D002404:Catheterization / Q000295:instrumentation; D003672:Defecation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D012007:Rectum / Q000502:physiology*; D012018:Reflex / Q000502:physiology*