Journal of Applied Physiology, Vol 41, Issue 5 677-682, Copyright © 1976 by American Physiological Society
Relationship between viscoelastic properties of the rectum and anal pressure in man
P. Arhan, C. Faverdin, B. Persoz, G. Devroede, F. Dubois, C. Dornic and D. Pellerin
Viscoelastic properties of the rectal wall and anal sphincter pressure were
studied simultaneously in 25 normal children. During rectal distension for
60 s, with varying volumes of air, the rectal pressure varied as the sum of
two exponential functions of the time plus an asymptotic constant. A
rectoanal inhibitory reflex was elicited during these distensions. The
exponential decrease of the rectal pressure corresponded exactly to the
return of the upper anal canal pressure to the resting value in some
subjects. In others, the upper anal canal remained relaxed as long as the
rectal ampulla was distended, except with smaller volumes. The results
obtained may be explained by an analogical rheological linear model.
