Anorectal Dysfunction and Obstetric Anal Sphincter Injury in Females

Abstract

Disorders of defaecation and bowel continence affect millions worldwide, and can have

profound impacts for individuals and the healthcare system. Increasingly recognised is the high prevalence of these conditions in females compared to their male counterparts. Despite these differences, there remain gaps in our knowledge regarding the anorectal physiological changes and long-term outcomes for these patients.

Following a comprehensive review of the literature, chapter 3 examines data from a prospective randomised study of the use of a footstool during defaecation in managing constipation, assessed by the balloon expulsion test. Footstool use did not change measures of evacuation in patients with undifferentiated constipation. However, it may be useful in the subset of constipated patients with dyssynergic defaecation. Chapter 4 describes the physiological changes of the anorectum associated with isolated flatus incontinence compared with healthy controls and females with faecal incontinence (FI). An association between isolated flatus incontinence and impaired anorectal physiology was identified, which correlated with poorer measures of quality of life. Chapter 5 and 6 explore the longterm clinical and physiological changes that occur in a group of patients who have experienced an obstetric anal sphincter injury (OASI) and assess if any baseline symptoms or physiology can predict the development of longterm FI. The novel findings in these two chapters provide a better understanding of anorectal function over time, and identify predictors of longterm FI in this group of patients.

In summary, the body of work in this thesis provides new insights into the clinical and physiological characteristics of patients experiencing constipation, flatus incontinence, and OASI. Furthermore, it highlights gaps in current knowledge and provides a focus for future studies to better understand these common but often suboptimally treated disorders that preferentially affect females.