Shah SC, et al. - Using population-based cohorts of patients with inflammatory bowel diseases (IBD) for which incidence and age data were available (17 distinct cohorts from 16 regions of Europe, North America, Australia, and New Zealand), the researchers examined sex differences in IBD incidence according to the age of diagnosis. Data were collected through December 2016 on 95,605 incident cases of Crohn’s disease (CD) and 112,004 incident cases of ulcerative colitis (UC). They found the age of IBD onset to vary with sex. In patients with epigenetic and genetic risk factors, sex hormones could affect the pathogenesis of IBD.