New insights into the pathophysiology and evaluation of fecal incontinence

This thesis presents new insights into the underlying pathophysiology and diagnostic process of fecal incontinence. Fecal incontinence is characterized by the involuntary loss of feces. It not only has a significant economic impact, but also negatively affects quality of life. We demonstrated that 7.9% of the general Dutch population suffers from fecal incontinence. It is often underdiagnosed because a considerable part of the Dutch population does not recognize it as a problem and people do not readily discuss their bowel habits with physicians. We also showed that certain comorbidities, rather than delivery history, anal sphincter injury, and increasing age, are associated with fecal incontinence. Moreover, we elucidated the different mechanisms underlying urge and complete fecal incontinence and postulated a new theory that overreaction of the anal-external sphincter continence reflex the cause is of chronic anal fissures. We developed the Groningen Defecation and Fecal Continence questionnaire to improve the screening of the possible causes of bowel disorders. We also demonstrated that the use of pull-through maneuvers and water-perfused catheters during anorectal manometry give unreliable results because they artificially increase anal basal pressure. Finally, only performing endo-anal ultrasound or three-dimensional anorectal manometry is insufficient to determine the underlying cause of fecal incontinence and neither technique should be used for this purpose. The findings described in this thesis broaden the knowledge on fecal incontinence and provide a foundation for further investigation of the pathophysiology of fecal incontinence and for improvement of its assessment and treatment