De chirurgische betekenis van de inwendige kringspier van het anale kanaal : een klinisch en manometrisch onderzoek

textabstractThe high pressure zone within the anal canal is largely due to the activity of the internal anal sphincter and provides an effective barrier against rectal pressure. The continuous contraction of the internal sphincter also has a congesting effect on the vascular cushions, thereby making the anal canal airtight and watertight. The internal anal sphincter thus seems to be an important factor maintaining faecal continence. Evidence has accumulated which suggests a possible role for this sphincter muscle in the pathogenesis of anorectal disorders. The aim of the study, described in this thesis, was to investigate the importance of the internal anal sphincter in the pathogenesis as well as in the surgical treatment of perianal abscesses, hemorrhoids and anal fissures