Table 3

Effect of the menstrual cycle on anorectal motility parameters

MensesFollicularLutealPremenstrual
Results are expressed as geometric mean (95% confidence interval (CI)).
Ratio is menses:period concerned.
Mean difference is with respect to menses plus 95% CI.
Cstat, static compliance; Cdyn, dynamic compliance; IAS, internal anal sphincter.
Cstat (ml/cmH2O) 4.1 (2.0, 7.5) 3.3 (2.0, 5.1) 4.0 (2.4, 6.4) 4.2 (3.4, 5.0)
    Ratio 1.2 (0.8, 1.7) 1.0 (0.4, 2.4) 1.0 (0.5, 2.1)
Cdyn (ml/cmH2O) 0.53 (0.45, 0.61) 0.48 (0.39, 0.56) 0.53 (0.45, 0.62) 0.55 (0.47, 0.62)
    Mean difference 0.06 (−0.14, 0.25) 0 (−0.14, 0.14) −0.02 (−0.15, 0.12)
Motility index759 (140, 4108)686 (26, 17534)780 (111, 5414)516 (123, 2159)
    Ratio 1.1 (0.2, 7.4) 1.0 (0.32, 3.0) 1.5 (0.7, 3.2)
Basal anal pressure (cm H2O) 76.1 (68.8, 84.2) 77.7 (72.0, 83.7) 79.2 (71.3, 88.0) 78.4 (71.9, 85.6)
    Ratio 1.0 (0.9, 1.1) 1.0 (0.9, 1.0) 1.0 (0.9, 1.0)
Initial IAS relaxation (ml) 11.8 (10.5, 13.2) 11.8 (10.5, 13.2) 11.2 (10.1, 12.3) 12.7 (10.4, 15.3)
    Ratio 1.0 (0.8, 1.2) 1.1 (0.9, 1.2) 0.9 (0.7, 1.1)
Sustained IAS relaxation (ml) 94.4 (70.2, 126.7) 86.2 (78.4, 94.8) 76.0 (54.9, 106.1) 78.9 (55.2, 112.6)
    Ratio 1.1 (0.8, 1.6) 1.2 (0.7, 2.1) 1.2 (0.8, 1.7)