Oral 5‐aminosalicylic acid showed no clear difference in adverse event compared with sulfasalazine (moderate certainty).
It is very uncertain whether azathioprine changes failure to maintain remission compared with sulfasalazine (very low certainty).
It is very uncertain whether mesalamine changes induction of remission (CDAI < 150) or clinical improvement ‐… compared with sulfasalazine (alone or (very low certainty).
Azathioprine or 6‐mercaptopurine showed no clear difference in maintenance of remission compared with mesalazine or sulfasalazine (low certainty).
It is very uncertain whether azathioprine or 6‐mercaptopurine changes adverse events compared with mesalazine or sulfasalazine (very low certainty).
It is very uncertain whether azathioprine or 6‐mercaptopurine changes withdrawals due to adverse events compared with mesalazine or sulfasalazine (very low certainty).
It is very uncertain whether azathioprine or 6‐mercaptopurine changes serious adverse events compared with mesalazine or sulfasalazine (very low certainty).