Swash M
Trans Med Soc Lond. 1984;101:53-7.
In idiopathic anorectal incontinence there is weakness of the pelvic floor sphincter muscles. This is evident on digital examination of the external anal sphincter muscle, and can be confirmed by anorectal manometry. This pelvic floor weakness is commonly associated with abnormal descent of the pelvic floor below the plane of the perineum during straining, as during the act of defaecation. This perineal descent is itself a feature of weakness of these muscles as shown by the prominent appearance of this sign in patients with cauda equina lesions. Almost all patients with this syndrome are women and there is usually a history of prolonged or difficult childbirth, often followed by a change in bowel habit, with prolonged and persistent straining at stool. However, not all affected women have experienced childbirth. In the latter a similar pattern of abnormal defaecation is present, but the reason for this is unknown. Anorectal incontinence is associated with urinary incontinence of the stress type in 10-15% of patients.
特发性肛门直肠失禁患者存在盆底括约肌肌肉无力的情况。这在外括约肌的指诊中很明显，并且可以通过肛门直肠测压得到证实。这种盆底无力通常与用力时盆底下降至会阴平面以下有关，比如在排便时。正如马尾神经损伤患者中该体征的显著表现所示，这种会阴下降本身就是这些肌肉无力的一个特征。几乎所有患有该综合征的患者都是女性，通常有分娩时间延长或分娩困难的病史，随后常伴有排便习惯改变，排便时会长期持续用力。然而，并非所有受影响的女性都经历过分娩。在后者中也存在类似的异常排便模式，但原因不明。10% - 15%的患者的肛门直肠失禁与压力性尿失禁有关。
