A good place to start would be here as they list a few doctors that currently treat for this based on
location. Perhaps a better idea would also be to request that your GI call them and discuss their success/failures/side effects and such first hand.
www.crohnsmapvaccine.com is the main website
and this is the direct link to the specialists by geographic area - though the list is small at the moment -
crohnsmapvaccine.com/map-specialists-2/