Anthony, I'm not suggesting that Gibblets should suddenly start consuming bowls of nothing but rice. But rather introduce a selection of whole grains (well cooked, of course) alongside vegetables and easily digestible beans, and just see how he/she gets on.
This is also why I queried Gibblets' symptoms.
I'm sorry to read that such grains cause you difficulties (I seem to recall you writing about the benefits of brown rice in previous posts...?), however please try to understand that everyone responds differently to changes in diet. Now, it could be that introducing some brown rice etc. does indeed lead to a flair-up of Gibblets' symptoms, but if not, it's a very nutritious form of energy that tastes delicious, so is surely worth a try. ;)
I do not believe that grains in themselves are damaging - if this was the case, civilisations throughout the world that rely on them as a key source of energy would no longer exist.