Physio-pathology of the internal anal sphincter.

In normal physiological studies, using electrical, manometric, or cinematographic methods, it is practically impossible to separate the role of the internal sphincter from that of the other elements of the functional ensemble forming the anal sphincteric system (Aron and Thouvenot, 1962; Lawson and Nixon, 1967; Schnaufer et al., 1967). It is only by studying the pathology of the area that it is possible to have an idea of what may be the role of each of the elements of this system in recto-anal continence. I should like, today, to summarize for you the research which I have for some years been undertaking on the neuro-anatomy and the physiology of the internal anal sphincter (Duhamel, 1967; Duhamel and Pages, 1968; Pages, 1967).