Apologies for sounding rude (it's my style, or lack thereof!), but you say "The mesalamines have worked for keeping the Crohns at bay for about
5 years, and I'm glad."
Yet you just had a colonoscopy that shows you have active disease and need a stronger med. This means that the mesalamines have NOT worked, not at all, at keeping the Crohn's at bay. You might have felt ok on them the last five years, but they were not doing their job, or you wouldn't be in the position you are in now.
Like I said, apologies for being so blunt.