Anorectal manometry in hirschsprung's disease - abstract

ABSTRACT

Normal anorectal reflexes are a relaxation of the internal anal sphincter and a simultaneous contraction of the external anal sphincter, in response to rectal distension. The internal anal sphincter (involuntary, smooth muscle sphincter) relaxation is mediated via a local reflex arc involving the ganglion cells in the bowel wall. Whereas the external sphincter (voluntary, striated muscle) contraction involves a spinal relex arc with afferent limb through the hypogastric nerves, efferent limb through the pudendal nerves and the neurons in the sacral segment of the spinal cord. Hence the study of the response of the anal sphincters to rectal distension, i.e. anorectal manometry, provides information about the functional state of the muscle and the integrity of the reflex arcs. This forms the basis for its apllication in the diagnosis of congenital aganglionic megacolon (hirschsprung's disease) (AU)