An experimental study on the mechanism of rectosphincteric reflex in special reference to Hirschsprung's disease.

In order to clarify the mechanism of rectosphincteric reflex (RSR), an experimental study was performed using mongrel canine models. The RSR exists in normal anesthetized mongrel dogs. It does not disappear in dogs with isolation of the rectoanal portion from the surrounding tissues. The RSR disappeared after circular transection of the rectal muscle coat at the level between the rectum and the anal canal, and also after selective destruction of the myenteric plexus of the rectum. These data suggest that the RSR is a local reflex contained within the rectoanal wall and its regulating center and neural pathway are in the myenteric plexus of the rectum.