I've had chronic canker sores since my Crohn's started in 2005. I mean, 5-20 at a time, ALL the time. Once I started on the 5-ASA meds they decreased in severity and frequency to the point that I don't have them all the time.
I just had a flare in Feb/Mar and those suckers are big and painful! Hard to eat, hard to talk. Miserable all around. I did use a dental paste called Triaminclone that helped but wasn't a magic bullet.
I find that if I eat sugar candy (M&Ms and skittles in particular) I can immediately trigger a huge canker sore. They seem to form where the food touches my mouth - the roof and in between my upper molars and cheek. They are deep pits. Each lasts about 2 weeks. I have permanent scars on the inside of my cheeks from biting them when my entire mouth is swollen.
What works for me: avoiding all sugar (especially those citrus type candies) and gluten, and staying on my meds.
Hope you find something that works.
"What can't be changed must be endured" - unknown
DX with distal Crohn's colitis Oct 2007, predominantly in rectum
Colozal and Canasa for 2+ years - developed an intolerance
6MP - elevated LFTs after 100mg, no effect after 9 months
Currently: Remicade (Nov '09), and Paleo Diet. Not quite remission, but so much better!