Little bag pipe cat

Hi all

I am a little stumped on this one. Poor Tarka's tummy has STILL not settled down. She still has a runny tummy and she is still very bloated with gas - she looks like a bag pipe. I have taken her to the vet, he has now got her on a 10 day course of Flagyl (I am aboout day 4 into it) but it hasn't helped at all! How long should it take to work. The poor thing waddles around as though she is pregnant (which I know she isn't)...

Any thoughts?

Oh, and I have changed their food from Royal Canin for kittens to Hills Science Diet for kittens (about a month ago) - made no difference. Little Luca is absolutely fine.