Background: Fistulas are a common complication of Crohn's disease (CD) and are difficult to treat effectively. This Study aimed to assess the effects of fistula on annual costs of healthcare and resource utilization for patients with CD. Methods: A retrospective analysis, using the PharMetrics database, of patients with a diagnosis of CD from January 1, 2000 through June 30, 2005 was conducted. Using paid claim amounts, healthcare costs and resource utilization were compared for patients with and without fistula in the year following diagnosis. Further analysis compared costs for adult, pediatric, and older adult patients with and without fistula. Results: This analysis included 13,454 patients with CD, of whom 12,683 (94.3%) had no diagnosis Of fistula. The total median (range) cost per patient was higher for the fistula cohort ($10,863 [$0-$1,307,019]) than the nonfistula cohort ($6268 [$0-$1,181,485]) driven mainly by higher hospital and surgery costs. Median healthcare costs and resource utilization rates were generally higher for patients with fistula compared with those without fistula in all 3 age groups, with some of the largest differences observed in the pediatric cohort. Conclusions: Fistulas are often a difficult and costly complication of CD. This study determined that patients with fistulizing CD have higher healthcare costs and resource consumption than patients Without fistula. Use of therapies that heal fistulas may help deter some of the high costs and intensive resource utilization found in this study. Economic analyses need to account for these issues when assessing the cost-effectiveness of therapies targeting fistulizing disease.