Table 3.
Effect of the menstrual cycle on anorectal motility parameters
| Menses | Follicular | Luteal | Premenstrual | |
| 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 index | 759 (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) |
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.