Ella was diagnosed with reflux by pead - but early childhood nurse had pretty much told me so before i was able to see pead. I was told to use Karicare food thickner, then we were put on zantac. Try not to let them be flat on their back - even when changing nappy or at playtime. This worked a little but dd was still quite distressed by it. EC nurse suggested a local Osteopath that had worked wonders for other bubs. So we saw him. After about 3 sessions there was a HUGE difference and after 6-8 her reflux had completely gone! I'd never even heard of an osteopath helping reflux but i now would highly recommend them. It wasn't very expensive, very gentle (most of the time ella was asleep...just like a gentle massage) and didn't take very long.
Good luck with what u try - hope it gets sorted for ur little one