Sounds like EN.
It is important and to inform your dr. about this. Maybe call him and speak to him and tell him whats going on, and ask him what he thinks (if you should wait or come in earlier than your next appointment).
I was diagnosed with UC a year ago, was on prednisone for 3 months and as i was tapering off it, i developed EN. Your story sounds exactly like mine. I thought it was a bite or twop and didnt even consider going to the dr abt it until they got bigger and uncomfortable, hot to the touch etc. He switched me to 6MP (Mercaptopurine) which does the same kind of thing as Prednisone but does not have the same side effects as it. cleared up within a few days and never heard from since.
Dx: Dec. 2006 with UC
F, 23, NYC
Thank G-d - Prednisone then 6MP, Rowasa and Asacol brought remission
Now Asacol 4tabs 2x a day.
Muiltivitamin, Iron and Folic Acid supplements