Enteric Infection in Relapse of Inflammatory Bowel Disease: The Utility of Stool Microbial PCR Testing

Background: The similar presentations in relapse of inflammatory bowel disease (IBD) and enteric infection pose substantial barriers to diagnosis and treatment. The objective of this study was to investigate the incidence, etiology, predictors, and treatment of enteric infection in patients with IBD. Methods: We reviewed the records of 214 patients with IBD who underwent 295 gastrointestinal pathogen panel and Clostridium difficile infection (CDI) polymerase chain reaction (PCR) stool tests during an exacerbation of symptoms. We collected baseline characteristics, PCR outcomes, and medication exposures. We tested for associations via the Chi-square test and the t-test. Logistic regression analysis was used to identify predictors of enteric infection. Results: Of 295 PCR tests ordered during an exacerbation of symptoms, 38 (12.9%) were positive for CDI and 41 (13.8%) were positive for 14 other pathogens, with E. coli species as the most common. A previous history of CDI or colonic involvement of IBD predicted CDI, whereas a previous colectomy predicted negative testing for CDI. The majority with CDI (24, 63.2%) received oral vancomycin and 15 (37.5%) with other enteric pathogens were treated for their infection. Patients with CDI had a longer median length of hospital stay (8.5 versus 4 days, P = 0.041). Patients who tested negative for enteric infections were more likely to have IBD medications added or up-titrated (P = 0.027). Conclusions: Enteric infection was detected in 79 (26.8%) symptomatic patients with IBD, with CDI the most frequent followed by E. coli. Negative stool PCR testing was associated with changes in IBD management. Broad enteric PCR testing should be considered during relapse of IBD.