A0256 - Is Rectal Sensitivity a Marker of Irritable Bowel Syndrome in Chronic Constipation?

Artemis Trikola, MD, Janavi Sethurathnam, BSc, Kelly Buchanan, MD, Nir Bar, MD, Christopher Velez, MD, Braden Kuo, MD, Kyle Staller, MD, MPH
Massachusetts General Hospital, Boston, MA

Introduction: Sensory testing is a standard component of anorectal manometry (ARM), but controversy exists about its clinical value. Patients with irritable bowel syndrome (IBS) are traditionally thought to be hypersensitive to rectal balloon inflation. We sought to determine whether rectal hypersensitivity was a marker of IBS in a large cohort using multiple different technologies.

Methods: We analyzed data from consecutive patients undergoing ARM for chronic constipation between July 2017 and April 2022. We collected demographics; disease characteristics including Rome IV IBS diagnosis and symptom severity (via Patient Assessment of Constipation Symptoms (PAC-SYM)); and psychological features including anxiety/depression (Hospital Anxiety and Depression Scale (HADS)) and GI-specific anxiety (Visceral Sensitivity Index (VSI)). We correlated this data with ARM sensitivity measurements, which were collected with both high-resolution (HR) and 3D ARM catheters. Volume measurements >75th percentile of first sensation, urge sensation and maximum tolerable volume were defined as hypersensitivity in order to homogenize differences in HR and 3D ARM measurements. We used logistic regression to examine associations with rectal hypersensitivity.

Results: We recruited a total of 456 patients (mean age 49.5+/-17.5 years, 90.0% female), who predominantly met Rome IV criteria for functional constipation (FC)((n=405, 88.8%) vs n=51 (11.2%) with IBS-C)). Patients with IBS-C tended to have more severe constipation symptom severity (driven by abdominal symptoms subscale) and increased GI-specific anxiety relative to patients with FC (Table). There were no differences in proportion of hypersensitive patients for any threshold between the groups (Table). Age-adjusted logistic regression demonstrated that IBS-C was not associated with rectal hypersensitivity at first sensation volume, (OR=0.61, 95% CI 0.30-1.15, p=0.14), urge sensation volume (OR=0.75, 95% CI 0.38-1.43, p=0.40), or discomfort volume (OR=0.78, 95% CI 0.38-1.50, p=0.47).

Discussion: In this large cohort of patients undergoing ARM for chronic constipation using two different types of ARM catheter technology, we found no evidence to support increased rectal sensitivity to volumtetric inflation in IBS patients relative to those with functional constipation. These findings indicate that rectal sensation may not be reflective of the visceral hypersensitivity thought to drive underlying disease pathophysiology in IBS.



Disclosures:


Artemis Trikola, MD, Janavi Sethurathnam, BSc, Kelly Buchanan, MD, Nir Bar, MD, Christopher Velez, MD, Braden Kuo, MD, Kyle Staller, MD, MPH. A0256 - Is Rectal Sensitivity a Marker of Irritable Bowel Syndrome in Chronic Constipation?, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.