Background and Aim Inflammatory bowel disease (IBD) and diverticulitis both increase morbidity, especially when associated with in-patient hospitalization. This study aimed to evaluate whether hospitalization burden differs for diverticulitis in patients with a history of Crohn's disease (CD) compared to ulcerative colitis (UC). Method All patients hospitalized for acute diverticulitis with pre-existing UC or CD in 2014 were selected using the national in-patient sample. Cases were identified using the International Classification of Diseases, Ninth Edition codes. Primary outcomes were mortality, cost of admission, length of stay (LOS), and colectomy. Results A total of 1815 patients were admitted with diverticulitis, and those with CD had a hospitalization associated with decreased cost (aOR -14 537, 95% CI -27 316 to -1758; P = 0.026) and LOS (aOR -1.31, 95% CI -2.41 to -0.208; P = 0.02) compared to UC. A second analysis comparing diverticulitis hospitalization between those with CD and those with the absence of IBD showed no significant difference in mortality (aOR 2.47, 95% CI 0.59 to 10.36; P = 0.22), LOS (aOR 0.03, 95% CI -0.47 to 0.54; P = 0.92), or cost of admission (aOR -2196, 95% CI -6933 to 2539; P = 0.36) between the cohorts. Conclusion Patients with UC have worsened hospitalization outcomes when being treated for diverticulitis compared to CD. While the findings may be a result of a difference in colectomy rates, the etiology may also be multifactorial. These conclusions have not been previously described, and further investigations would better characterize these associations.