Epidemiology and Mechanisms of Fecal Incontinence

大小便失禁（FI）是老年妇女的社会破坏性症状，可能有助于制度化。特发性FI的流行病学和病理生理学尚不完全清楚。目前基于三级保健研究的概念非常强调肛门括约肌缺陷通过肛门超声显像的作用。初步研究表明，奥姆斯特德县50岁以上妇女FI患病率为17.8%，中位发病年龄为61岁。产科事件、腹泻/急症和肥胖是FI的危险因素。我们的新型“透视”单次快速自旋回声MRI技术实时显示排便时盆底下降。与US相反，肛门内MRI显示外括约肌缺陷和萎缩，耻骨直肠变薄和整体盆底松弛。假设大便失禁不是单纯由产科创伤所致，而是由产科创伤、过度劳损、肥胖、衰老、更年期等引起的盆底无力，再加上腹泻的累积结果。这一假设将通过结合罗彻斯特流行病学项目的数据基础设施与社区样本中最先进的生理测量来解决。一份调查问卷将邮寄给大约1000名妇女的队列，以确定FI的发病率和自然史，并将邮寄给5000名妇女的新样本，以确定FI的患病率和频率。骨盆底损伤的推定危险因素（产科创伤、慢性紧张、肥胖和雌激素消耗）和FI（腹泻和直肠急症）将在一项病例对照研究中进行评估，该研究包括约200名FI患者，每月至少一次，约200名对照组。大约100名FI患者和大约100名对照患者将接受MRI透视检查，以表征与FI相关的特定整体盆底异常（即肛门括约肌缺陷、括约肌萎缩、耻骨直肠变薄和盆底松弛）。这些研究将完善我们对FI流行病学的理解，确定导致盆底损伤延迟表现的产科危险因素，强调非产科危险因素对FI的重要性，并为社区中与FI相关的盆底损伤的特定模式提供新的见解。这些步骤对于通过改变危险因素来减少骨盆底损伤的发生率，识别进展为症状性FI的高风险患者，并设计适当的干预措施来阻止这一过程是必要的。

Fecal incontinence (FI) is a socially devastating symptom in older women and may contribute to institutionalization. The epidemiology and pathophysiology of "idiopathic" FI is incompletely understood. Current concepts based on tertiary-care studies heavily emphasize the role of anal sphincter defects visualized by endoanal ultrasound. Preliminary studies suggest that the prevalence of FI in Olmsted County in women greater than or equal to 50 years is 17.8 percent with a median age of onset of 61 years. Obstetric events, diarrhea/urgency and obesity are risk factors for FI. Our novel "fluoroscopic" single-shot fast spin-echo MRI techniques visualize pelvic floor descent during defecation in real-time. In contrast to US, endoanal MRI depicts external sphincter defects and atrophy, puborectalis thinning and global pelvic floor laxity. The hypothesis is that fecal incontinence is not attributable to obstetric trauma alone, but the cumulative result of pelvic floor weakness caused by obstetric trauma, excessive straining, obesity, aging and menopause, compounded by diarrhea. This hypothesis will be addressed by combining the data infrastructure of the Rochester Epidemiology Project with state- of-the-art physiological measurements in a community-based sample. A questionnaire will be mailed to a cohort of approximately 1,000 women surveyed previously to ascertain the incidence and natural history of FI, and, a new sample of 5,000 women to determine the prevalence and frequency of FI. Putative risk factors for pelvic floor injury (obstetric trauma, chronic straining, obesity and estrogen depletion) and FI (diarrhea and rectal urgency) will be evaluated in a case-control study of approximately 200 patients with FI at least once a month and approximately 200 controls. approximately 100 patients with FI and approximately 100 controls will have MRI fluoroscopy to characterize the specific global pelvic floor abnormality (i.e., anal sphincter defects, sphincter atrophy, puborectalis thinning and pelvic floor laxity) associated with FI. These studies will refine our understanding of the epidemiology of FI, identify the obstetric risk factors responsible for delayed manifestations of pelvic floor injury, i.e. FI, underscore the importance of non- obstetric risk factors for FI and provide novel insights into the specific pattern of pelvic floor injury associated with FI in a community. These steps are necessary for reducing the incidence of pelvic floor damage by risk factor modification, identifying patients at higher risk of progressing to symptomatic FI, and designing appropriate interventions to halt this process.