You ask if anyone else has this problem, the lack of response suggests they have not (rather than indifference to your suffering). usually the forum is a prelude to a doctor visit, but it sounds as if you have already exhausted doctor's advice so you can't really expect the forum to have immediate answers for you I'm afraid.
You say your doc has treated you for all the common issues like sibo and pouchitis, Scott has recommend a specific drug you could ask to try.
Then you say you have tried the diet changes, such as excluding dairy and gluten. What happens if you fast? Ie just drinking water. Does the gas improve or get worse? Presumably that would indicate if it was related to the intake of food. If it doesn't improve I guess it would have to be something like sibo or you are gulping air without realising it (perhaps in sleep?)
I'm sure you've tried this but do high dose probiotics help? Which one did you try? Digestive enzymes (proper ones not Beano) might help too.
Have you tried playing with fibre? Benefibre gave me terrible gas, but on psyllium and inulin it often firms me enough so I can pass gas sitting or even walking which might be a boon in your situation.
Please don't think people on the forum don't want to help, but it seems you have tried a lot of the stuff we would advise anyway and people probally don't want to post just to say they don't have any advice for you.
I hope you find the solution to this soon