There is controversy over the role of the type 2 immune response in pathogenesis of ulcerative colitis (UC)—few data are available from treatment-naïve patients. We investigated whether genes associated with a type 2 immune response in the intestinal mucosa are upregulated in treatment-naïve pediatric patients with UC, compared to patients with Crohn’s disease (CD)-associated colitis or without inflammatory bowel disease (IBD), and whether expression levels associate with clinical outcomes.