Influence of age and sex on anal sphincters: manometric evaluation of anorectal continence.

To investigate the exact nature of anorectal continence, a manometric evaluation was performed in 88 healthy test persons with a two-balloon catheter. The pressure in the anal canal (PAC) and the rectal ampulla at rest (PAR), the maximum squeeze pressure (PAC max) and pressure rise in the anal canal after dilatation of the rectal ampulla delta PAC) were evaluated separately for men and women, and the test persons were divided into 3 age groups (group I: under 40 years, group II: 40-60 years, group III: over 60 years). PAC showed a statistically significant difference between men and women and a constant decrease with age--statistically significant for men and for women between groups II and III--whereas the statistical significance of the 3 other values had to be restricted to a constant decrease with advance in years. Anorectal continence is characterized by a PAC at rest of over 40 mm Hg, a PAC max reaching at least 80 mm Hg, a pressure gradient between rectal ampulla and anal canal of over 20 mm Hg and a delta PAC of more than 10 mm Hg. These values as well as the differences depending on age and sex should be kept in mind for the evaluation of the continence function.