Physiologic Basis Of Digital–Rectal Stimulation For Bowel Evacuation In Patients With Spinal Cord Injury: Identification Of An Anorectal Excitatory Reflex

Abstract

Anal dilatation induces rectal contraction through stimulation of mechanoreceptors, possibly in the internal sphincter. Rectal contraction upon anal dilatation suggests a reflex relationship that was absent on individual anesthetization of the possible 2 arms of the reflex arc: anal canal and rectum. This relationship, which we term the "anorectal excitatory reflex," appears to be evoked on digital anal dilatation. The reflex might be of diagnostic significance in defecation disorders and has the potential to be used as an investigative tool.