Hi @cfarrugia
My son is currently 8wks and we've had similar issues.
Like yours, my little one takes a bottle every 3 hours, and that IS feeding on demand, he has his own little routine that varies some days but for the most part he's asked for a feed every 3 hours since his birth.
For us, DS struggled to pass gas and was crying/visibly uncomfortable all day long, poor thing. So we swapped from Aptamil 1 to Aptamil Comfort for colic and constipation.
This is when our reflux woes started, the origin formula was too heavy in his stomach and his wind couldn't pass through it, but the new formula was top thin and wouldn't stay down.
The trapped wind and all the exhausting symptoms that came with it had all but gone, however he'd project full bottles after feeds.
I spoke to GP who gave us infant gaviscon, but that just thickens the milk and takes us back to square one with the wind and honestly didn't help with the reflux anyway.
DH brought home a box of Aptamil Reflux Formula. I haven't been brave enough to try him on a full bottle yet. It has thickening agents in it, so again, heavier with the idea it will stay down. But I've read lots of reviews stating its caused constipation in baby as its so thick it won't even come out of the bottle.
I decided to mix 1oz of reflux milk with 4oz of comfort in hopes of thickening the comfort just enough to hold it down but sadly this hasn't worked for us. He no longer projects but still brings up food/sick 3 and 4 hours after a feed, any time he's lay on his back.
Intact I came on here to find some advice myself, as he's currently lay in my chest sobbing after another failed attempt and solving reflux woes has left him with trapped gas again. I'm pulling my hair out.
I'm at the point that I'd rather the reflux than the trapped gas, atleast reflux doesn't seem to upset him.
My cousin swears by a 50/50 mix of aptamil 1 and aptamil reflux. I known this won't work for my little one but perhaps worth a go for yours? Do some reading up on mixing formulas, my HV has told me it's safe to do and lots of mums on here have experience with it top.
Just be wary of swapping one problem for another as I seem to have :(