There is all kinds of info throughout this site on LDN. Things started for me via a link to a study presented in the American Journal of Gastro-enterolgy in early 2007 by Dr Jill Smith at Penn State. Go the AJG website, search on it, and printout the synopsis of the study. It should get your GI's attention. There have been others, you can probably find links to them in various posts in here. Dr Smith has just done another on LDN in pediatric Crohns.
4.5 mg trial dose of Naltrexone is (in my humble, but totally untrained opinion) far safer than stem cell transplants or surgery. If you can convince your GI to give it a chance for 3 months AND your CDAI (CDIA?) scores don't improve, then talk about operations or transplants. But, first do your homework, legwork. Get printouts of as many studies as you can, especially those from recognized sources, prestigious schools and journals. If those fail to give your GI food for thought, then you're wasting your time trying to sway him/her. My anecdotal success story (or the others who also take LDN) probably won't influence your doctor. But if he reads sound studies, done by real doctors, then it may.