Hi. The first link I posted to this thread is the Digestive and Liver Diseases Clinic in Dallas. I believe fairly large with pre-FDA approved clinical trials like alot of us are on. Good Luck
Follow the link and use the search function to find a trial in your area that will fit your needs
http://clinicaltrials.gov/ct2/search/advanced
Might have to copy and paste the link.
Might call these folks.
http://www.utswmedicine.org/hospitals-clinics/outpatient/digestive-liver-diseases/