I didn't understand the wording "every time I step outside to his cage" - what does that mean? If you keep him outside...there would be so many things I'd be worrying about, but for now I'll focus on the poo thing bc if you DO keep him outside - one thing I'd bc concerned about is intestinal parasites...he should have a fecal done if you're keeping him outside.
As far as the poo in general - he almost sounds as if he is having 'fatty stools' - and that is not good or normal. Explosive, voluminous, foul, light colored stools are absolutely not normal - definitely speak with your vet and either switch to another appropriate food ASAP, or, take him in to be seen. The fact that's he having bad gas is another clue - there is clearly some major irritation going on in GI system, and it's probably very uncomfortable for him; there could be ingredients that just are not suitable for his system.
Was he a rescue, since you got him at age 5?
I hope you can find a solution for him. He sounds like a real sweetie and I bet his life would be a whole lot happier without all the digestive distress. Your life too
!