INTRODUCTION: Inflammatory bowel disease (IBD) and celiac disease (CeD) are immune-mediated diseases characterized by chronic intestinal inflammation. Some studies have suggested that patients with both IBD and CeD carry a higher risk of hospitalization and severe disease as compared with non-celiac IBD patients. This study aimed to evaluate the prevalence of CeD, the impact of CeD on outcomes among IBD hospitalizations and compare outcomes in subgroups of Crohn’s disease (CD) and ulcerative colitis (UC). METHODS: The NIS was used to identify adult patients with IBD hospitalizations from 2010 to 2014 using ICD-9 codes. Primary outcomes were mortality, hospital charges, length of stay (LOS) and colorectal surgery. The secondary outcome was the trend of the prevalence of CeD in IBD hospitalizations. Subgroup analysis was performed for UC with vs without CeD and CD with vs without CeD. Propensity scoring methods and multivariate regressions were used. RESULTS: There were 516,891 IBD related hospitalizations from 2010 to 2014, of which 1582 patients had CeD. The control group consisted of 7913 IBD hospitalizations without CeD. The average age of patients having CeD with IBD was 43.5 years old, 32.0% were male and 81.6% were Caucasian. IBD with CeD was associated with a lower rate of colorectal surgery compared to IBD without CeD (4.06% vs 5.90%, aOR 0.62, 95% CI = 0.47–0.81, P-value <0.001), but differences in mortality rate, LOS, and hospital charges were not significant. The prevalence of CeD in patients with IBD related hospitalizations increased from 0.23% to 0.45%. The annual percentage change (APC) of the prevalence of CeD in patients with IBD related hospitalizations was 0.058 (95% CI = 0.026–0.089, P-value <0.05). Subgroup analysis showed CeD was associated with a lower rate of colorectal surgery in adult patients with CD (1.2% vs 2.1%, aOR 0.36, 95% CI = 0.18–0.72, P-value <0.05) and was not associated with different outcomes in UC hospitalizations. CONCLUSION: The prevalence of CeD in IBD hospitalizations from 2010 to 2014 increased. This may be a result of increased awareness and testing for CeD. CeD was associated with a lower rate of colorectal surgery in CD and was not associated with different outcomes in UC. This may be explained by CD phenotypes with CeD that elicits a small bowel predominant presentation leading to lower colorectal surgery rates. Further studies are required to evaluate the pathogenesis of CD with CeD and its effects on clinical outcomes of hospitalized patients.Figure 1.: The trend in prevalence of celiac disease in patients with inflammatory bowel disease-related hospitalizations from 2010 to 2014.Table 1.: Comparison of baseline characteristics of patients admitted for inflammatory bowel disease (IBD) with celiac disease vs. without celiac diseaseTable 2.: Crude and Adjusted results for inpatient outcomes in patients with inflammatory bowel disease (IBD) with vs. without celiac disease from 2010 to 2014 *Adjusted for age, gender, race, primary insurance payer, hospital type, hospital bed size, Elixhauser comorbidity index score and income quartile