My son now aged 13 was under GOS hospital for a number of years. He was tested for crohn's which came back negative, however he suffers with awful uclers in his mouth. They are not your average ulcer they measure up to 1cm and he usually gets a few at a time. GOS put him on 'pentasa' for a while and he has had a couple of endoscopies and colonoscopies. These show his colon and intestines to be clear. So we were discharged from GOS care. The flare-ups he gets with his uclers are now treated by our doctor who perscibes steriods. My sons bottom lip is so swollen that the steriods are the only thing which seems to bring down the swelling but I am nervious about the slide effects the tablets may have on my son. No one seems to know why my sons gets these flare-ups and we just get told he will grow out of it!!!!!