Background & Aims

The contribution of the abdominal muscles to normal defecation and disturbances thereof in defecatory disorders (DDs) are unknown.

Methods

In 30 healthy and 60 constipated women with normal rectal balloon expulsion time (BET) (n = 26) or prolonged BET (ie, DD; n = 34), seated anorectal pressures (manometry) and thickness (ultrasound) of the external and internal oblique and transversus abdominis muscles were measured simultaneously at rest, during hollowing, squeeze, evacuation, and a Valsalva maneuver.

Results

Compared with healthy women with a normal BET, DD women had a lower rectal and greater anal pressure increase during evacuation (P ≤ .05), and more activation of the internal oblique and the transversus abdominis muscles during squeeze (P < .05). The change in transversus abdominis thickness during a Valsalva maneuver vs hollowing (rho = 0.5; P = .002) and separately vs evacuation (rho = 0.7; P < .0001) were correlated in DD but not in healthy women with a normal BET. A principal component (PC) analysis of anorectal pressures and muscle thicknesses during evacuation uncovered a PC (PC3) that was associated with a prolonged BET. Higher PC3 scores were associated with low rectal and high anal pressures at rest and during evacuation, thinner external oblique muscle, and thicker internal oblique muscle during evacuation. A greater PC3 score was associated with increased odds for DD vs health (odds ratio, 1.84; 95% CI, 1.05–3.23), and separately vs constipation with a normal BET (odds ratio, 3.64; 95% CI, 1.73–7.69).

Conclusions

Taken together, these findings show 3, possibly inter-related, disturbances suggestive of dyscoordination in DD: aberrant activation of abdominal muscles during squeeze in DD, dyscoordination of the abdominal muscles during various tasks in constipated women, and abdomino-anal dyscoordination.

中文翻译：

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排便障碍中的腹肛失调

背景与目标

腹部肌肉对正常排便的贡献及其在排便障碍（DD）中的干扰尚不清楚。

方法

在 30 名健康女性和 60 名便秘女性中，直肠球囊排出时间 (BET) 正常（n = 26）或 BET 延长（即 DD；n = 34），坐位肛门直肠压力（测压）和外部和内部的厚度（超声）在休息、空腹、挤压、排空和瓦氏动作期间同时测量腹斜肌和腹横肌。

结果

与 BET 正常的健康女性相比，DD 女性在排便期间直肠压力较低，肛门压力增加较大 ( P ≤ .05)，并且在挤压期间内斜肌和腹横肌的激活更多 ( P < .05)。Valsalva 动作与空腹动作 (rho = 0.5; P  = .002) 以及单独与清空动作 (rho = 0.7; P < .0001)期间腹横肌厚度的变化在 DD 中相关，但在 BET 正常的健康女性中则不相关。对排便期间肛门直肠压力和肌肉厚度的主成分 (PC) 分析发现，PC (PC3) 与延长 BET 相关。较高的 PC3 评分与静息时和排便期间的低直肠压力和高肛门压力、排便期间外斜肌较薄以及内斜肌较厚有关。较高的 PC3 评分与 DD 与健康人群的比值增加相关（比值比，1.84；95% CI，1.05–3.23），并且与正常 BET 的便秘相比，单独比值增加（比值比，3.64；95% CI，1.73–7.69） 。

结论

总而言之，这些发现显示了 3 种可能相互关联的干扰，提示 DD 中的协调失调：DD 中挤压期间腹部肌肉的异常激活、便秘女性在各种任务中腹部肌肉的协调失调以及腹-肛门协调失调。