A man is preparing a hamburger at the kitchen table, and he is using a plastic ketchup bottle to squeeze ketchup onto his burger. It's two-thirds empty, so it makes "farting" noises as he squirts ketchup onto his burger. His girlfriend tells him it's gross and to stop, but he can't help it. But then he gets a brainwave, and he heads for the kitchen cabinet, where he gets out a bottle of Gas-X, and gets a tablet, which he then puts into the bottle of ketchup, and then he shakes the ketchup bottle. Then he squirts the ketchup, and it makes no noise whatsoever.
And this is a metaphor for what Gas-X does for people who are gassy: it stops the farting.
(Now, naturally, there would have to be some disclaimers on this ad's lower third, like: "Dramatization", and: "Do Not Attempt." Because after all, this sort of smooth move only works for people in ads. And we don't want regular, everyday, normal people starting to think they can be cool too like ad people. Because, really: who wants to live in a world like that?)
