Changes in characteristics of gastroenterology center inpatients in Japan because of rapidly aging society

Background and Aim Rapidly aging societies have become a major issue worldwide including Japan. This study aimed to elucidate relative changes in the characteristics of inpatients in Japan related to this issue. Methods A total of 23 835 Japanese inpatients treated from 2010 to 2021 were enrolled (2010–2013, period I; 2014–2017, period II; 2018–2021, period III). Changes in clinical features were retrospectively analyzed based on ICD‐10 diagnosis data. Results The percentage of patients aged over 75 years increased over time (period I, 38.0%; II, 39.5%, III, 41.4%). Emergency admissions comprised 27.5% of all in period I, which increased to 43.2% in period II and again to 44.5% in period III (P