I would call your doctor. I got mouth ulcer while on 6-MP. Turns out I was so immuno-suppressed that I got bone-marrow failure. Happened quickly too. Within 3 weeks. I ended up in isolation for 10 days. I suggest getting a blood test just to be on the safe side.
Vicky / 47 years old
DX'd with Crohn's during a resection August 2006
DX'd with Steriod induced Diabetes November 2006
Considered in Clinical remission but have minor signs of disease activity
Daughter (26) also has Crohn's since she was 12.
Currently on 4000mg of Pentasa only for Crohn's
No longer able to take 6-MP because of Bone-Marrow Suppression
Cymbalta, Metformin, Lipitor