Hiraoka S, Fujiwara A, Toyokawa T, et al. - As some patients with ulcerative colitis (UC) show symptoms of intolerance towards mesalamine (the first‐choice drug for treating mild‐to‐moderate UC), researchers sought to ascertain the current state and clinical courses of patients with mesalamine intolerance. They performed analysis of 633 patients who were diagnosed with UC and were administered oral mesalamine at eight hospitals in Japan with a follow‐up period exceeding 1 year. Among these, 67 (11%) displayed intolerance to at least one formulation of oral mesalamine. Per findings, the frequency of mesalamine intolerance has been increasing recently. Exacerbation of diarrhea, fever, and abdominal pain were the most frequent complications reported. They identified following factors to be associated with the risk of mesalamine intolerance: female gender, age < 60 years old, and pancolitis. Outcomes revealed no significant differences in the prognosis of patients with mesalamine intolerance vs those without intolerance.