EC Gastroenterology and Digestive System

Much of current knowledge of the evacuation phenomenon in humans has followed closely and, in some cases, has literally walked on the wheels of diagnostic imaging. Over the past several years the technological advances in the field of body imaging have been too numerous to catalogue. Still today the innovations follow one another at an uncessant pace so that as soon as a new proposal appears on the horizon, there is not enough time to investigate it before a further one is already outlined.

At the very beginning of the experience, researchers were mainly concerned with (a) how to implement such a private function as evacuation in a “hostile” laboratory environment and (b) how to achieve on command such an act that is usually obtained at will only in the presence of an adequate sensation of fullness. In practice, two methods of simulated defecation were developed which were essentially based on one of the following lines: a radiolabelled synthetic potato mesh was inserted intrarectally until reaching the need to evacuate and the dynamic changes during simulated defecation were recorded using a gamma camera, a method also known as Isotope Dynamic Proctography; a semisolid barium sulfate suspension, alone or in combination with a potato mesh, was administered in the same way and rectal emptying was documented with cine fluorography, a method universally known as X-ray Dynamic Proctography. In both cases, the completeness and rapidity of rectal emptying, the changes in the angulation of anorectal junction, and the extent of its downward displacement, combined with the presence of well established morphologic changes of the contrast filled gut profile - whether protruding outward, intraluminally or outside the anal verge - are subsequently correlated with symptoms to help physicians obtaining a more confident diagnosis and decide proper therapy, accordingly.