The act of defaecation, although a ubiquitous human experience, requires the coordinated actions of the anorectum and colon, pelvic floor musculature, and the enteric, peripheral and central nervous systems. Defaecation is best appreciated through the description of four phases, which are, temporally and physiologically, reasonably discrete. However, given the complexity of this process, it is unsurprising that disorders of defaecation are both common and problematic; almost everyone will experience constipation at some time in their life and many will develop faecal incontinence. A detailed understanding of the normal physiology of defaecation and continence is critical to inform management of disorders of defaecation. During the past decade, there have been major advances in the investigative tools used to assess colonic and anorectal function. This Review details the current understanding of defaecation and continence. This includes an overview of the relevant anatomy and physiology, a description of the four phases of defaecation, and factors influencing defaecation (demographics, stool frequency/consistency, psychobehavioural factors, posture, circadian rhythm, dietary intake and medications). A summary of the known pathophysiology of defaecation disorders including constipation, faecal incontinence and irritable bowel syndrome is also included, as well as considerations for further research in this field.

排便行为虽然是一种普遍存在的人类体验，但需要肛门直肠和结肠、盆底肌肉组织以及肠道、外周和中枢神经系统的协调行动。通过描述四个阶段来最好地理解排便，这四个阶段在时间和生理上是相当离散的。然而，鉴于这一过程的复杂性，排便障碍既常见又存在问题也就不足为奇了。几乎每个人都会在一生中的某个时候经历便秘，许多人会出现大便失禁。详细了解排便和节制的正常生理学对于告知排便障碍的管理至关重要。在过去十年中，用于评估结肠和肛门直肠功能的调查工具取得了重大进展。本评论详细介绍了当前对排便和失禁的理解。这包括对相关解剖学和生理学的概述，对排便四个阶段的描述，以及影响排便的因素（人口统计、大便频率/一致性、心理行为因素、姿势、昼夜节律、饮食摄入和药物）。还包括对包括便秘、大便失禁和肠易激综合征在内的排便障碍的已知病理生理学的总结，以及该领域进一步研究的考虑。心理行为因素、姿势、昼夜节律、饮食摄入和药物）。还包括对包括便秘、大便失禁和肠易激综合征在内的排便障碍的已知病理生理学的总结，以及该领域进一步研究的考虑。心理行为因素、姿势、昼夜节律、饮食摄入和药物）。还包括对包括便秘、大便失禁和肠易激综合征在内的排便障碍的已知病理生理学的总结，以及该领域进一步研究的考虑。