Rectal Compliance Lower Than Normal in Ulcerative Colitis, but Recovery Is Possible

By Marilynn Larkin

October 08, 2021

NEW YORK (Reuters Health) - Rectal compliance is lower in ulcerative colitis (UC) patients than in those without UC, but recovery is possible, researchers suggest.

"The findings did not surprise us, but supported our hypothesis that patients with UC have reduced compliance of their rectum, even when they are in remission," Dr. David Rubin of the University of Chicago Medicine Inflammatory Bowel Disease Center told Reuters Health by email. "The exciting new finding is that those who normalized their histology - i.e., biopsies show no evidence of chronic colitis - had compliance similar to the non-colitis control group."

"The findings emphasize that (in UC), there is damage and an impact on the function of the rectum with chronic injury," he said. "This primary finding explains some of the discrepancy between symptoms and endoscopic findings, and drives home the important and newer goal of treating beyond symptom control to bowel healing as a target of therapy."

"The finding that the normalized bowel had compliance similar to the non-colitis individuals suggests that there may be remodeling of the bowel with stable deep remission," he noted. "This has been seen in other injury states, like post-myocardial infarction cardiac remodeling."

As reported in Gastroenterology, the team enrolled 73 patients with UC (51% women; 71% with extensive disease; mean disease duration, 16.9 years) and 20 non-IBD controls. Demographics were similar between the groups except for age: the mean was 51.5 for UC participants and 61.1 for controls.

All participants underwent a barostat examination, in which a rectal balloon was incrementally insufflated to an initial pressure of 5 mm Hg and up to a maximal pressure of 60 mmHg, and the corresponding rectal balloon volumes (mL) were measured by the barostat.

Static rectal compliance was lower in patients with UC, even after adjustment for age (= 265.7 mL vs. = 311.1 mL). Patients with UC who had Simplified Clinical Colitis Activity Index (SCCAI) scores of five or more had lower compliance than those with a score <5, and the Mayo endoscopic subscore had a negative effect on compliance.

A history of biologic therapy was associated with reduced compliance (=244.07 mL vs. = 290.64 mL). However, disease duration, disease extent, age, and sex were not associated with differences in compliance.

A histologic disease analysis showed that 28 patients had active inflammation and 22 had quiescent disease, whereas 23 normalized their histology.

Rectal compliance was lower in those with active histologic disease (=247.6mL) compared to non-UC controls (V = 311.1 mL) and to those with quiescent disease (= 265.3 mL).

Further, the histologically quiescent group had lower rectal compliance ( = 265.32 mL) compared to the control group (= 311.1 mL).

However, as Dr. Rubin noted, participants who normalized their histology had similar rectal compliance ( = 288.21 mL) to controls ( = 311.06 mL).

Gastroenterologist Dr. Shannon Chang, Director of clinical operations at NYU Langone's Inflammatory Bowel Disease Center in New York City, commented on the study in an email to Reuters Health. "Patients with UC do experience fecal urgency, and though this is most commonly thought to be due to active inflammation, this study suggests that other factors contribute to the sensation of fecal urgency," she said.

"This study only evaluated barostat pressures and rectal volumes while patients were sedated," she noted. "As such, the patients' sensation and symptoms of urgency were not able to be correlated with these findings. A good next step would be to see how these findings correspond with patient-reported sensations of urgency."

"A notable finding was that active histologic disease was associated with reduced rectal compliance when compared with quiescent and normalized histology," she said. "Patients with more active disease also had reduced rectal compliance. These findings further support the need to treat active disease aggressively to prevent long-term complications. Though histologic normalization is not yet a standard treatment goal, it may be a future target."

SOURCE: Gastroenterology, online September 28, 2021.