<prompt> What is true regarding sulfasalazine?Active moiety is 5 amino salicylic acid in ulcerative colitisInactive moiety is 5 amino salicylic acid in ulcerative colitisInactive moiety in rheumatoid ahritis is SulfapyridineIt gets activated in the stomach  <response>: Around 90 of a dose of sulfasalazine reaches the colon, where most of it is metabolized by bacteria into sulfapyridine and mesalazine also known as 5-aminosalicylic acid or 5-ASA.5 ASA is the active moiety produced in the colon in U.Colitis.In rheumatoid ahritis the active moiety is sulphapyridine.Ref: Katzung 13th ed. Pg: 1072 