<p><strong>BACKGROUND: </strong>Antibiotics are often given for inflammatory bowel disease (IBD) exacerbations, but their use among pediatric inpatients has not been assessed. We aimed to validate administrative data for identifying hospitalizations for IBD exacerbation and to characterize antibiotic use for IBD exacerbations across children's hospitals.</p>

<p><strong>METHODS: </strong>To validate administrative data for identifying IBD exacerbation, we reviewed charts of 409 patients with IBD at 3 US tertiary care children's hospitals. Using the case definition with optimal test characteristics, we identified 3450 children with 5063 hospitalizations for IBD exacerbation at 36 children's hospitals between January 1, 2007 and December 31, 2009, excluding those with diagnosis codes for specific bacterial infections. We estimated predicted and expected hospital-specific antibiotic utilization rates using mixed-effects logistic regression, adjusting for patient- and hospital-level factors.</p>

<p><strong>RESULTS: </strong>Administrative codes for receipt of intravenous steroids or endoscopy provided 79% positive predictive value and 71% sensitivity for identifying hospitalizations for IBD exacerbation. Antibiotics were administered for ≥2 of the first 3 hospital days during 40.7% of IBD exacerbations in US children's hospitals; however, the proportion of patients receiving antibiotics varied significantly across hospitals from 27% to 71% (P&nbsp;&lt;&nbsp;.001), despite adjustment for several patient- and hospital-level variables. Among those given antibiotics, the 3 most common regimens were metronidazole alone (26.9%), metronidazole with ciprofloxacin (10.3%), and ampicillin with gentamicin and metronidazole (7.0%).</p>

<p><strong>CONCLUSIONS: </strong>Significant variability exists in antibiotic use for children hospitalized with IBD exacerbation, which is unexplained by disease severity or hospital volume. Further study should determine the optimal antibiotic therapy for this condition.</p>