The main reason I don't do the diet is that I'm not that bad off since being in a trial for FMT. Labs are all within normal limits and my last scope a couple of months back looked fine. I do have some mild symptoms (may be more IBS than IBD now) and some foods I still need to stay away from, but what variables would I be modifying, and how would I track success? If anything, since I would consider my FMT successful- at least for now, my thought would be that starving bacteria would cause the transplanted guys to be killed as well, and that's the LAST thing I would want.
FMT is not a cure by any means, and no doubt I will flare again, but for now, I don't think it's necessary. In terms of diet, I think it's also way too simplistic to think in terms of just carbs and bacteria. Resistant starches actually improve colonic butyrate, so things like potatoes should be fine. Gluten is an issue for many, not really because of bacteria, but because in many it's immunogenic. Even those with conditions other than IBD and no problems with gut flora do better off gluten because in some people gluten triggers immune reactions. Why? who knows.
I've done my own food diaries for days at a time (I've been at this about 11 years now.) Rice, potatoes never bother me, in fact- they are my go to foods when things have gotten rough. For a book to declare them "illegal" without controlled studies or looking at my scope or biopsies is ridiculous.
I've said it before and I'll say it again. Inflammation in the TI is not the same at all as inflammation in the rectum. stenosing and fistulizing disease is not the same as nonspecific inflammation. Kids are not adults. Other medical conditions, medications, environment etc... all play a role in this disease. To say "cut out all complex carbs and all will be well" is simplistic, scientifically unproven, and in some potentially dangerous. It's also potentially socially isolating in a condition that already does that. It can create a fear of food in a disease that already has apprehension of food. Don't get me wrong, diet is a HUGE part of IBD management. But at this point the best we can all do is trial and error.
Show me labs, scopes, biopsies of those on the diet alone, diet and meds, meds alone, and let's start putting real data together.