S Hong et al. Inflamm Bowel Dis 2021; 27: 1634-1640. Comparative Evaluation of Conventional Stool Testing and Multiplex Molecular Panel in Outpatients With Relapse of Inflammatory Bowel Disease

In this retrospective cohort study with 268 adult patients with inflammatory bowel disease, the authors compared the use of a GI PCR panel with 22 analytes (BioFire) and C diff testing to ‘conventional’ stool testing (culture, O&P and C diff). Key findings:

• Pathogens were more frequently identified on GI PCR (26 vs 5%; P < 0.01)
• GI PCR was associated with less escalation in IBD therapy (16 vs 29%; P < 0.01) and fewer posttest endoscopies (10% vs 18%; P = 0.04), with no differences in IBD outcomes
• Those with recent travel had a higher pathogen detection rate: 38% vs 14%; P<0.01
• In the GI PCR group, the most common pathogens were E coli species 22 (including 12 Enteropathogenic E coli), Campylobacter 10, Multiple pathogens 7, Norovirus 6, Yersinia 3, C diff 3,

The authors note that the group who underwent GI PCR panel testing were more likely to present with severe symptoms (eg. fever, rectal bleeding) as well as a history of recent travel. Even when controlling for symptoms and biomarkers of inflammation, GI PCR testing was still associated with lower likelihood of escalating IBD therapies.

My take: This study indicates that identification of an infectious pathogen which is more likely with a GI PCR panel helps avoid escalation of IBD therapy and need for endoscopy in the outpatient setting.

Related blog post: Molecular Panels for Identifying Etiology with Acute GI Symptoms