While I don't have experience with dwarf gourami, I do have plentiful experience of bloated goldfish and goldfish with buoyancy problems. On the basis of that experience, I'd advise:
* feeding frozen, chopped peas ie blanch a pea so that the shell slips off easily; then keep chopping each of the halves into as many small morsels as you possibly can - put that in near the filter outlet, so that it disperses around the tank and the affected fish can get at least some to eat
* feeding frozen/live food (eg bloodworm, brineshrimp, daphnia) - like peas, this should also induce a clearout if there's any intestinal blockages causing the problem (such as having consumed the majority of that tablet a few days ago)
* frequent water changes - even 10% daily should help
My next stages of treatment, if the above didn't work, were aquarium salt which often had an overnight turnaround effect (but this isn't advised with many species of tropical fish so I'd avoid that if in any doubt) and finally medication (for bacterial infection).
If the scales look pineconed all over (as opposed to just slightly spread where the tummy is distended), then this indicates dropsy. There's no mistaking the pineconing look - it's the first thing you'd notice if it's happened.
If he looks as though it's struggling to eat, breathing heavily and behaving very differently, then I'd suggest medicating with Waterlife Myxazin or eSHa 2000 in a quarantine tank if you have one plus a filter that you can transfer some existing/established filter media into. Only fill it as much as is required to cover the filter - that way, if buoyancy starts to become a problem (eg sinking like a lead balloon to the bottom or floating up like a helium balloon to the top), then he doesn't have so far to swim up/down.
Best of luck and keep us posted on how he is.