Assessment of Anorectal Function in Patients With Inflammatory Bowel Disease

Active inflammatory bowel disease (IBD) causes disabling symptoms such as diarrhea, involuntary loss of bowel control, abdominal pain and urges to pass stool. However, even patients with inactive IBD frequently experience such symptoms. The cause is not well understood and the functionality of the bowel in IBD patients is underexplored.

Earlier studies show a wide range of results, but most find that patients with IBD in remission are up to four times as likely to report gastrointestinal symptoms when compared to healthy controls.

Chronic inflammation may cause changes of the bowel wall, like increased collagen deposits (fibrosis) and thus cause symptoms, but the absence of active inflammation in combination with presence of symptoms may also be regarded as resembling the clinical condition of irritable bowel syndrome (IBS).

IBS is characterized by abdominal pain and changes in stool frequency and consistence and is often associated with disorders like depression and anxiety. Up to a third of IBD patients without signs of disease activity meet the criteria for IBS (irritable bowel syndrome. It can be speculated that an IBD diagnosis is a distressing event that can induce mood disorders, and an IBS-like condition.

Characterization of IBS patients relies on the Rome IV symptom criteria, symptom severity scales and measurements of rectal sensibility and rectal compliance using a barostat procedure.

Motor function assessment relies on anorectal manometry which detects abnormalities of muscle function and coordination. Recently, a standardized high-resolution anorectal manometry protocol (HRAM) was published which also evaluates sensitivity and compliance. The level of agreement between the barostat method and the HRAM testing procedure regarding sensibility and rectal compliance is largely unknown.

Recent studies have associated gut microorganisms, genetic factors, and proteins with various aspects of IBD. There is evidence that these potential markers may reflect non-inflammatory processes such as fibrosis.

The aim of this study is to explore the anorectal function in symptomatic patients with inactive IBD compared to healthy volunteers and asymptomatic patients, evaluate symptom severity and psychological parameters and perform molecular characterization.

The level of agreement of rectal sensitivity and compliance measurements with the barostat method and HRAM protocol will also be evaluated.