11.   Burleigh previously reported similar actions for N-monomethyl-L-arginine and L-arginine on eurogenic relaxation in human internal anal sphincter smooth muscle.

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

13.   In contrast, none of the spinal patients produced an increase in anal pressure or an increase in external anal sphincter activity when asked to contract their sphincter.

14.   Rectal contractions were associated with prolonged increases in external anal sphincter activity and anal pressure in all normal subjects.

15.   Internal anal sphincter relaxation increased in amplitude and duration in all spinal patients and normal controls as the rectum was distended intermittently with increasing volumes.

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

17.   In normal subjects, the internal anal sphincter showed anal pressure increases upon deflating the rectal baloon that exceeded the predistending values.

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

19.   Giant contractions were always associated with enhanced internal anal sphincter relaxation and induced spontaneous balloon evacuation in nine patients.

20.   These observations reinforce the notion that the external anal sphincter response to increases in intra-abdominal pressure is a spinal reflex, triggered by tension receptors in the pelvis floor.