Predictors of irritable bowel syndrome-like symptoms in quiescent inflammatory bowel disease

Many patients with quiescent inflammatory bowel disease (IBD) suffer from irritable bowel syndrome (IBS)-like symptoms. Although these symptoms cause significant reductions in quality of life, evidence-based treatments are lacking as risk factors and pathophysiology of these symptoms are not clearly defined. We aimed to identify risk factors for development of IBS-like symptoms in IBD patients with quiescent disease.

We performed a single-center retrospective cohort study of adults with IBD from 2015 to 2021. Quiescent IBD was defined by a fecal calprotectin level <250 μg/g of stool or endoscopic evidence of quiescent disease. Cox regression was performed to identify variables that were independently associated with the incident development of IBS-like symptoms in IBD patients.

A total of 368 IBD patients were included for analysis, including 278 patients with UC and 88 with Crohn's disease. 15.5% of quiescent IBD patients developed IBS symptoms, with an incidence rate of (95% CI 48.0-82.0) 63.3 per 1000 person-years. In the multivariate model, mood disorders (including anxiety and depression) and Crohn's disease were associated with increased risk for developing IBS symptoms. Male sex and higher iron levels conferred lower risk for developing IBS symptoms. Results from the multivariable model were similar in sensitivity analysis with quiescent IBD defined by fecal calprotectin level <150 mcg/g.

Mood disorder and Crohn's disease were positively associated with IBS-like symptoms in quiescent IBD, whereas male sex and iron levels were protective. Our results were robust to different fecal calprotectin levels, arguing against inflammation as a mechanism for IBS-like symptoms. This data suggests noninflammatory mechanisms may be important in the pathogenesis of IBS-like symptoms in quiescent IBD. Future work may address whether modifying these risk factors may alter disease course.