It's nothing to do with C or D. I am C too but I certainly don't get the unwelcome symptoms IBS-unfriendly food induces merely the next day... I get them after a meal containing IBS-unfriendly ingredients. Sometimes within minutes/half an hour but definitely within a couple of hours and not the next day.
-------------------- Susie, born in 1985,
(pseudo-)D and bloating April 2007-December 2010, now stable