Department of Colorectal Surgery, Digestive Diseases and Surgery Institute, Cleveland Clinic Foundation, Cleveland, Ohio.
Dis Colon Rectum. 2019 Apr;62(4):510-512. doi: 10.1097/DCR.0000000000001257.
Patients undergoing an IPAA experience a completely different physiology of defecation than when they had a rectum. The new "normal" is poorly appreciated and incompletely understood, and the lack of understanding has implications for pouch function. This technical note lays out the physiology of defecation with an ileal pouch and its implications for patients and surgeons.
An intestinal pouch acts as a reservoir because the united antegrade and retrograde peristaltic loops produce no evacuatory pressure. Defecation occurs by gravity. Efficient defecation results in fewer stools, but inefficient defecation may cause stool frequency, incontinence, obstruction, constipation, and pouch inflammation. The technical aspects of pouch construction that impact emptying include a long efferent limb of an S-pouch, any degree of twist in the pouch body, afferent limb syndrome, and anal stenosis.
Constructing a pouch with no twists and with an open anus, maintaining liquid stool, and encouraging unhurried defecation can improve pouch function.
Understanding pouch physiology is important in optimizing pouch function and maintaining patient expectations.
接受 IPAA 手术的患者经历了一种与直肠完全不同的排便生理。新的“常态”被理解得很差，也不完全被理解，缺乏理解对袋功能有影响。本技术说明阐述了带有回肠袋的排便生理学及其对患者和外科医生的影响。
肠袋作为一个储袋，因为联合的顺行和逆行蠕动环不会产生排空压力。排便靠重力。有效的排便会减少粪便的次数，但无效的排便可能会导致粪便频率增加、失禁、梗阻、便秘和袋炎。影响排空的袋结构的技术方面包括 S 袋的长输出段、袋体的任何程度的扭曲、输入段综合征和肛门狭窄。
构建一个没有扭曲、肛门开放、保持液体粪便、并鼓励从容排便的袋可以改善袋功能。
了解袋生理学对于优化袋功能和维持患者期望非常重要。
