[Effect of the menstrual cycle on the reproducibility of anorectal manometry]

The influence of the menstrual cycle on the reproducibility of anorectal manometry was investigated in 6 healthy volunteers (median age 29 years) without hormonal treatment, who were studied during the follicular and the luteal phases and during the menstruation phase. The intra- and interindividual variations were compared by calculating KENDALL's concordance coefficient. The following results were obtained (mean +/- SD): sphincter length (41 +/- 4 mm), anal pressure at rest (79 +/- 6 cm H2O) and during voluntary contraction (167 +/- 23 cm H2O), threshold volume for the anorectal reflex (12 +/- 3 ml), duration after 20 ml (24 +/- 7 seconds), after 40 ml (47 +/- 3 seconds) and variation of the rectoanal inhibitory reflex after 40 ml (25 +/- 9 cm H2O), threshold volume of rectal sensation (16 +/- 5 ml), volume of constant perception after 30 seconds (101 +/- 27 ml), maximum tolerable volume (212 +/- 18 ml) and rectal pressure during maximum tolerable volume (23 +/- 6 cm H2O). For all of the above parameters, the intra-individual variations were not higher than the inter-individual variations. We therefore conclude that the menstrual cycle does not influence the reproducibility of anorectal manometry in the healthy woman.