If it is the swim bladder, their is not much you can do, except for ensuring that you have good water quality.
but it could also be internal bacteria, I would do a 30-50% waterchange, and add some internal bacteria medicine just to be safe.
I would also repeat the waterchange in 2-3 days.
Thanks for the feedback guys, hes doing just fine now. i didnt do anything apart from a water change 20-30%, and the next day he was back to normal.
I got the Rhom from a place called 'birstall garden center' its in leicester, UK. They have a pretty good aquatics section. cost 4.70. had to place a special order took 2 weeks shipping from brazil they told me "shrug" ? a friend of mine brought 2 RBP's from there also, there doing great, around 5-6" now.