Table 1.
Anal manometry and anal balloon distension
| Parameter | Healthy women (n=33) | Constipated women (n=17) | P-value |
|---|---|---|---|
| Anorectal manometry | |||
| Anal pressure at rest, mm Hg | 90 (25) | 94 (26) | .59 |
| Anal canal length, cm | 3.2 (1.1) | 3.8 (.7) | .02* |
| Anal pressure during squeeze, mm Hg† | 235 (53) | 194 (53) | .01* |
| Anal pressure during evacuation, mm Hg | 71 (25) | 86 (28) | .06 |
| Anal pressure change (after – before) during evacuation, mm Hg | −19 (28) | −8 (19) | .1 |
| Rectoanal gradient during evacuation, mm Hg | −34 (26) | −58 (40) | .03* |
| Anal distension with MRI – actual parameters | |||
| Opening pressure, mm Hg | 49 (18) | 46 (19) | .68 |
| Balloon diameter at Prhalf, cm | 1.7 (.8) | 1.9 (.8) | .47 |
| Balloon volume at Prhalf, ml | 7.8 (4.9) | 7.7 (4.3) | .98 |
| Slope for balloon diameter, mm Hgĉm | .05 (.03) | .04 (.03) | .41 |
| Slope for balloon volume, mm Hĝml | .30 (.18) | .35 (,29) | .95 |
| Maximum balloon pressure, mm Hg | 84 (14) | 85 (15) | .66 |
| Maximum balloon diameter, cm | 2.2 (.7) | 2.5 (.6) | .24 |
| Maximum volume, ml | 11.8 (6.2) | 12.5 (4.8) | .77 |
| Anal distension with MRI – estimated parameters | |||
| Opening pressure, mm Hg | 49 (21) | 50 (25) | .86 |
| Balloon diameter at Prhalf, cm | 1.7 (.5) | 1.7 (.7) | .85 |
| Balloon volume at Prhalf, ml | 6.6 (3.5) | 7.8 (5.7) | .54 |
| Maximum balloon pressure, mm Hg | 88 (14) | 90 (13) | .92 |
| Maximum balloon diameter, cm | 2.1 (.7) | 2.4 (.8) | .28 |
| Maximum balloon volume, ml | 11.1 (5.8) | 14.5 (8.5) | .18 |
| Anal distension without MRI – estimated parameters | |||
| Opening pressure, mmHg | 46 (26) | 44 (26) | .96 |
| Balloon diameter at Prhalf, cm | 1.4 (.6) | 1.4 (.8) | .97 |
| Balloon volume at Prhalf, ml | 5.3 (4.7) | 6.2 (5.8) | .73 |
| Maximum balloon pressure, mm Hg | 86 (20) | 93 (14) | .18 |
| Maximum balloon diameter, cm | 2.3 (.8) | 2.2 (.8) | .99 |
| Maximum balloon volume, ml | 12.4 (7.8) | 13.1 (8.2) | .59 |
| Sensory thresholds | |||
| Pressure threshold for first sensation, mm Hg | 34 (26) | 41 (28) | .07 |
| Volume threshold for first sensation, ml | 1.3 (1.6) | 3.3 (3.8) | .02* |
| Pressure threshold for desire to defecate, mm Hg | 53 (29) | 48 (30) | .54 |
| Volume threshold for desire to defecate, ml | 3.8 (5.1) | 4.4 (4.6) | .75 |
| Pressure threshold for urgency, mm Hg | 69 (28) | 57 (28) | .34 |
| Volume threshold for urgency, ml | 6.3 (6.8) | 6.3 (6.1) | .72 |
†
These values are derived from the squeeze maneuver with the highest squeeze pressure
*
P<0.05