Wow what a topic that I so much wish I could give you all the answers. I have had Crohn's for 11 years and have been to Disney many times since. I have never had a flare there. I swear Disney is magical for me and my DH is convinced it is my way of trying to talk him into moving there!
Seriously though, all of us have great advice in how we handle it, but one thing about this disease is it definitely affects everyone differently. If I were to eat Rice on my diet I would be in the hospital the next day. I am allergic to rice and tomatoes - oh not the severe allergy like a peanut allergy. But the more subtual allergy- if I eat it once -maybe do ok, if I eat it twice in a few days - definitely going to have a flare. I found this out by a blood test after suffering with Crohns for too long and wanting desperately to understand why from day to day it changes.
http://www.gdx.net/home/assessments/allergy/ this is the test I took if you are interested. Not sure if they have something similar in Canada. My wonderful Crohn's doctor just smiles when I say I know what triggers my flares, but let him smile... I have tested it too many times and I am the one suffering each time. The doctors have no clue what causes this yucky disease so essentially each of us have to be our own doctor.
By the way, I am so sorry to hear that you don't have a doctor? I don't really understand how that can be. I thought Canada had a national health plan and everyone gets care all the time. At least that is what they are telling us in the US so we can get our national health care plan. Can you enlighten us why your DBF wouldn't have a doctor or meds yet?

That is just crazy and I feel terrible that he can't get relief.
Meds that have worked for me - Remicade it was a miracle for me and put me into remission many times. Got too used to it and decided I didn't want to do the maintenance rounds and then low and behold I developed an immunity to the drug and my throat started to swell. Not good. Next will be Humira which is a doing great for Crohn's and two new drugs are just being released with great promise. But for flares I always go with my trusty Prednisone. And yes this is the drug that will make you have mood swings with LONG term use or at high doses. But for a trip to DW I would do a Prednisone Push in which I would start a few days before I went and start with a Higher dose (40 mg) and wean down each day until off completely. My doc started me doing that one year right before we went to Disney and it was a great trip because I did not have any flares and the Prednisone makes your really hungry and everything tastes good! Of course you would need a doctor to allow this and prescribe, but it always works for me to get me through this kind of trip.
Last year I had flares prior to a trip. Did a Predsinone push and went to Disney. NO PROBLEMS at all! Less than one week later I was in the hospital getting the intestine removed from a blockage.(No coinsidence that I had had Rice the night before at a Chinese restr. I just wanted a little -Stupid me!) The rice caused a inflamation and by this time the disease has caused enough scar tissue to creat the blockage. The disease just does damage the longer you have it and especially if you go without treating it or stopping the triggers. Please encourage you DBF to get some kind of treatment and if he can't get a Doctor yet, he most certainly can do a food journal and determine what trigger for him. It's not fun and not easy, but so worth it for me. I can eat lots of things, just stay away from my triggers.
I'm currently not on any medication unless I have a flare up then will go on Prednisone until I'm back on track. I've had Crohn's for almost 20 years. The biggest thing that helped me in the beginning was to keep a food journal. Write everything put in your mouth down along with your reaction that day. After a couple weeks look at it and see if you can spot any offending foods. I've found that what bothers one person doesn't bother the next so you really need to find what will work for the individual. Keep using the journal I used mine for over a year. Some foods I'm ok if I have it one day but two days in a row will cause a problem. It's all trial and error. Hope he finds a doctor soon.
I totally second this! Don't believe the doctors when they say it isn't food that is part of the "what causes" crohns. Yes Stress will flare you up bad, but to think that what we put into our gut doesn't somehow cause our gut to react against it to me is just crazy. Something triggers and for some of us it can be an allergy. If you are able at least get a skin allergy test to some common foods. And determine if there is one food that your DBF eat a lot of. Just a suggestion!
Oh and one poster mentioned a book and it might have been "breaking the Viscous Cycle" by Elaine Gottschall. It is a popular book about eating the right stuff for this disease. Now I agree with most of the book, but I also believe that alot of people who have success on this book, most likely have removed from their diet a trigger food. My sister and I both have Crohns and we are Italian and it used to be a joke that we would fight over who got the to the bathroom first after Sunday Sauce. Well now I know why since I have an allergy to tomatoes. We ate Tomato Sauce often 3 times a week growing up.
OK I know this has been long, Sorry. I wish you and your DBF a wonderful HEALTHY trip and bless you for being such a good girlfriend. This disease does not go away and I often think my husband is a saint having to deal with it right along with me! Hope all these suggestions from the great people on the DIS help you to have a magical vacation! I totally understand your DBF urge to not eat while away. Oh and does immodium work for him to stop or relieve the diahreah. OK. I am done now!!!