Wow, thanks, I never drew a distinction... For me it was - have to unbutton my trousers or looking in the mirror I decidedly look pregnant....(Even now btw it's not usually associated with pain either.) So always used bloating and distention and gas interchangeably for this condition..
So it's an acute problem with IBS, but certainly had this problem before IBS, and may have been due to fructans/lactose. I used to have white bread sandwiches and cheese, then had this problem. Then when I had a lot of wholemeal bread/breakfast cereal on a massive scale during the couple of months before IBS started I had no such problems anymore...(but wholemeal bread is a fructan too!)
-------------------- now: stable through EFI+FODMAP dieting (no lactose/no fructose/some fructans and some polyols)
before: IBS-D(pseudo-diarrhoea), bloating, often unbearable pain esp from too much fat: Apr 2007- Dec 2010