With great interest we have read the paper by Rungoe et al1 describing a possible decrease rate in surgery in patients with IBD. The authors have identified all Danish patients with IBD by their first IBD diagnosis registered in the time period from 1979 to 2011. Data were extracted from the Danish National Patient Register, which contains information about all inpatient hospital contacts including diagnoses and surgical interventions, and outpatient diagnoses were not registered before 1995. Accordingly, Cohorts 1 and 2 represent only patients, who have had conditions requiring first time admissions, whereas Cohorts 3 and 4 represent a mixture of patients having first time diagnoses of IBD as inpatients or as outpatients (probably milder cases). Thus, Cohorts 3 and 4 might represent patients with less severe disease at …