1.   It has been recognised for over a century that the internal anal sphincter relaxes in response to rectal distension, a phenomenon called the rectanal inhibitory reflex.

2.   Five minute rest periods separated each rectal distension.

3.   After each rectal distension, the subjects described their sensation.

4.   The validity of rectal distension measurements, usually determined with pressure-volume relations, is disputed.

5.   Sensations elicited by rectal distensions are the subject for research by several investigators.

6.   The occurrence and duration of external anal sphincter activity during rectal distension.

7.   There was no relationship between the level of the spinal lesion and the responses of the internal anal sphincter to rectal distension.

8.   The external anal sphincter responses to intermittent rectal distension were noticeably attenuated in spinal patients compared with normal subjects.

9.   Although the spinal patients had no specific rectal sensation during rectal distension, almost half of them experienced a dull pelvic sensation at maximum distension.

10.   The external anal sphincter response to rectal distension is very closely associated with both rectal sensation and rectal contraction in normal subjects, and presumably acts to prevent soiling.