The activation of these two systems is meant to be brief in response to acute emergency. When they become stuck (in either sympathetic overdrive or vagal overactivity), the survival function is drastically subverted: one may end up suffering from a painfully knotted gut, as in the case of persistent sympathetic hyperarousal, or be tormented by spasms of twisting cramps and disruptive diarrhea in chronic vagal hyperactivity.r
