Management of Bowel Dysfunction in Patients with Central Nervous System Diseases

Abstract

Pathologies affecting the central nervous system (CNS), involve alterations of digestive functions and, in particular, defecation disorders. This is not surprising when considering that the ability to control bladder and bowel emptying is the last function that the Homo sapiens “cub” learns. Even minor injuries of nerve pathways and control centers can easily compromise the integrated and delicate visceral, pelvic, and perineal dynamic. Reduced propulsion within the large intestine; abdominal-perineal dyssynergia due to deficiency and incoordination of pelvic floor muscles, associated with anorectal hyposensitivity; deficit of voluntary contraction of external anal sphincter; and abnormalities of internal sphincter reflex are the pathophysiological mechanisms underlying Neurogenic Bowel Dysfunction. Differently from bladder, in the digestive tract wall lies a neuronal network which is comparable, in terms of number and complexity of cells and connections, to the brain, which allows the bowel to have its own peristalsis even if totally isolated from CNS and ANS. Moreover, the type of content that is evacuated from the two organs: it is liquid from the bladder, from semiliquid to solid from the bowel and this is determined by the presence of bacteria originating from the colon microbiota, the most complex ecosystem in terms of microorganism concentration on the planet Earth. So, intestinal rehabilitation programs differ between bladder and bowel: bowel mangement considers drugs for improving propulsion of the colonic intraluminal content and assistence to rectal discharge, but also measures for guaranteing a regular volume and consistency of the fecal mass. Trans Anal irrigation have proven to be the best approach for restoring the physiologic features of defecations in these patients.