OBJECTIVES: To estimate the economic burden of coded postoperative ileus (POI) among patients undergoing open laparotomies in the US. METHODS: Using Premier's PerspectiveTM database, we identified 193,409 open laparotomy surgical patients based on their primary discharge ICD-9 procedure code during 2002. Coded POI was identified using ICD-9 diagnosis codes 560.1 and 997.4. Risk factors for coded POI were analyzed by a logistic regression model. To assess the economic burden of coded POI, multiple regression analyses were performed predicting hospital length of stay and total hospital costs while controlling for baseline variables. Estimates of incremental costs and length of hospital stay were projected to the national level. RESULTS: Extended operating room time increased the risk of coded POI by 20% for each one-hour increase (OR, 1.20, 95% CI, 1.19-1.21). Mean operating room time was 3.0±1.7 hours for patients with coded POI versus 2.5±1.2 hours for patients without coded POI. Use of PCA opioids increased the risk of coded POI by 39% (OR, 1.39, 95% CI, 1.34-1.44). Coded POI was associated with an additional 2.6 days (P<0.01) in the hospital and $1763 (P<0.01)in total hospital costs. For the US, the overall burden of coded POI for open laparotomies was estimated to be an additional 370,000 days in the hospital and $253 million in total costs. CONCLUSIONS: POI is associated with a significant economic impact. Inpatients with coded POI have extended operating time and increased use of PCA opioids. POI was also associated with increased hospital stay and consequently, hospital costs. Since POI may not be routinely coded in this database, the true economic burden of POI may be underestimated. Strategies to reduce the impact of POI should lead to economic savings to the hospital system.