Classification and clinical features of adverse drug reactions in patients with ulcerative colitis treated with 5‐aminosalicylate acid: a single-center, observational study

5-Aminosalicylate acid (5-ASA) is a crucial drug for ulcerative colitis (UC) patients. 5-ASA has several side effects. However, the types of side effects vary and are sometimes severe.A single-center, retrospective cohort study was conducted from September 2001 to June 2020. We surveyed consecutive UC patients who visited our hospital and investigated adverse drug reactions (ADRs) related to 5-ASA formulations. We grouped patients into four...