OBJECTIVES Constipation is prevalent in individuals after stroke. However, the pathophysiological mechanisms of poststroke constipation remain unclear. This study was designed (i) to investigate the difference in anorectal motility and rectal sensation among stroke patients with constipation, stroke patients without constipation, and healthy controls (HC), (ii) to evaluate the impact of stroke sites on constipation and rectal sensation, (iii) to explore the role of autonomic functions, and (iv) to determine the independent risk factors for poststroke constipation. METHODS Seventy-one stroke patients and 24 HC were recruited. General information, clinical characteristics, and relevant questionnaires were collected. Meanwhile, an anorectal manometry test was performed to assess functions of anorectal motility and rectal sensation, and an electrocardiogram was recorded to evaluate autonomic functions. RESULTS (i) Constipation patients exhibited increased rectal sensation thresholds, compared with patients without constipation or HC (P < 0.001). Almost no difference was detected in anorectal motility parameters among 3 groups. Constipation-associated clinical characteristics, such as spontaneous bowel movements, were weakly or moderately correlated with rectal sensation thresholds (P < 0.05 to P < 0.001 for various parameters). (ii) Patients with brainstem lesions had increased prevalence of constipation and first sensation threshold, compared with patients without brainstem lesions (P = 0.045, P = 0.025, respectively). (iii) There was a weak positive correlation between sympathetic activity and stroke severity and a weak negative one between vagal activity and stroke severity. Rectal sensation thresholds were positively and weakly correlated with sympathetic activity but negatively with vagal activity. (iv) The desire of defecation threshold and the physical activity were independent risk factors for poststroke constipation (P = 0.043, P = 0.025, respectively). DISCUSSION Poststroke constipation is characterized by elevated thresholds for rectal sensation, rather than altered anorectal motility. Patients with brainstem lesions are predisposed to constipation possibly because of the disruption of afferent pathway from the rectum to the brain. Moreover, the desire of defecation threshold and the physical activity level are factors independently associated with poststroke constipation.

中文翻译：

---

中风后便秘与直肠感觉受损有关

目的 中风后便秘在个体中很普遍。然而，中风后便秘的病理生理机制尚不清楚。本研究旨在 (i) 调查有便秘的中风患者、无便秘的中风患者和健康对照 (HC) 的肛门直肠运动和直肠感觉的差异，(ii) 评估中风部位对便秘和直肠感觉的影响, (iii) 探索自主神经功能的作用，以及 (iv) 确定中风后便秘的独立危险因素。方法 招募了 71 名中风患者和 24 名 HC。收集一般资料、临床特征和相关问卷。同时，进行肛门直肠测压测试以评估肛门直肠运动和直肠感觉的功能，并记录心电图以评估自主神经功能。结果 (i) 与没有便秘或 HC 的患者相比，便秘患者的直肠感觉阈值增加 (P < 0.001)。3组之间的肛门直肠运动参数几乎没有差异。便秘相关的临床特征，如自发排便，与直肠感觉阈值弱或中度相关（各种参数 P < 0.05 至 P < 0.001）。(ii) 与没有脑干病变的患者相比，有脑干病变的患者便秘和第一感觉阈值的患病率增加（分别为 P = 0.045、P = 0.025）。(iii) 交感神经活动与中风严重程度之间呈弱正相关，迷走神经活动与中风严重程度之间呈弱负相关。直肠感觉阈值与交感神经活动呈正相关和弱相关，但与迷走神经活动呈负相关。(iv) 排便阈值和体力活动是卒中后便秘的独立危险因素（分别为 P = 0.043、P = 0.025）。讨论 中风后便秘的特征是直肠感觉阈值升高，而不是肛门直肠运动的改变。脑干病变患者容易便秘，可能是因为从直肠到大脑的传入通路中断。而且，