Wow, 55g's of Vit C? At that level I'm amazed you didn't reach GI tolerance. Were you using a chewable vit C by any chance? My understanding is the body will take in as much vit C as it needs before passing the rest quickly through the colon. Thus, why it helps clear the intestines.
Have no thoughts on why you'd get gas from high Vit C levels but, doubt it was feeding candida or bacteria since Vit C is acidic and they both prefer and alkaline environment. In theory, all that acid if not absorbed should have helped destroy candida/bacteria: perhaps that is what caused the gas. I'd be interested to hear what others have to say about this.