Unraveling Anorectal Function and Biomarker Signatures in Patients Suffering From Subtypes of Defecatory Disorders

Defecatory disorders like chronic constipation and faecal incontinence affect 25% of the population with rising incidence. Defecatory disorders pose a major health care burden and are poorly recognized and treated. The need for better diagnostics and therapeutics is substantial. Currently management options for these patients are limited, partly due to the fact that control of defaecation and continence is multifactorial but also due to the fact that it is difficult to identify the exact cause of patients' incontinence. Even in healthy subjects, many aspects of defecatory mechanisms are yet not well understood.

Current assessment of patients with constipation and faecal incontinence include endoscopic assessment to rule out intraluminal organic cause for patients' symptoms, endoanal ultrasound scan / MRI to assess patients' pelvic floor anatomy and anorectal manometry and balloon expulsion test to assess anorectal function. All tests are susceptible to measurement artifacts, with a high inter-individual variation with significant overlap between healthy asymptomatic and symptomatic patients.

The standard technologies for anorectal assessment are anorectal manometry, ballon expulsion test and defecography. Endoluminal Functional Lumen Imaging Probe (EndoFLIP©) is a novel technology, originally used to measure the dimensions and function of a hollow organ. Anorectal manometry, balloon expulsion test, defecography, and the EndoFLIP probe will be used in the proposed studies. In addition, the proposed study intends to use a simulated feces named Fecobionics which is a device that integrates several technologies into one which will save time and reduce test variability. A major difference from EndoFLIP and other technologies like anorectal manometry is that the device will be defecated rather than providing static data from one location in the anal canal.

In the proposed studies investigators will assess defecatory function in subgroups of Hong Kong patients suffering from chronic constipation and faecal incontinence and determine biomarkers to increase the diagnostic value of anorectal testing. Investigators will study up to 130 patients with anorectal disorders and 101 healthy control subjects. Investigators anticipate to improve diagnostics of anorectal disorders considerably and to learn about physiological mechanisms that affect defecatory efficacy. For example, one substudy investigates the effect of posture on defecation and another substudy focuses on deferred defecation. A third study assessed defecatory parameters as a function of the stiffness of Fecobionics. Pelvic floor function will also be assessed through vaginal measurements as well as Fecobionics may be endoscopically placed in sigmoid colon. Finally, a substudy assessed intestinal parameters after insertion of Fecobionics through a stoma.