Hey sweetie,
Just a thought our LOs reflux/vomiting always seemed to get worse when he got constipated and Zantac (ranitidine) can cause constipation. Have you tried a little watered down prune juice to keep things moving for your LO?? It really really works.
I have a recipe which also works as they get a little older (more on solids) where you soak a couple of dried apricots and prunes in cold water for 2 hours, then simmer with water to just cover them...blend and give your LO a little bit (wait a while 'cause it can get things moving pretty quickly and give a little more if no action)...REALLY has helped our LO.
Reflux babies apparently commonly have a slowing of the lower gut which causes the constipation (and formula and reflux meds often exacerbate this), it's really nice to have a natural approach to helping this
Our LO just went through stages where the reflux was terrible and then it would settle for a few days and we would think it was getting better then it would go back to terrible again. We never had any intolerance diagnosed (no rashes, wheezing etc to indicate intolerance) and reflux isn't always a food related issue, sometimes just anatomical!!
Lili hang in there and get as much help as you can. As far as I know there is nothing that they can give to stop the throwing up (although our doctor suggested thickening our LOs bottles with 1 teaspoon of cornflour - make sure it's corn not wheat, and using normal formula because there wasn't an intolerance there and it was much cheaper than buying special thickened ones)...you can also add infant gaviscon to their bottles, this is a thickener and a mild antacid (but can also cause constipation so beware)...Hope you get some more answers soon, keep chatting it will really help
Lizzie