Hi there!! Matilda was on Gaviscon at first and you can get infant one from the chemist... its really safe, except it causes constipation in some, and it was awful constipation with Matilda. But apparently its a really good medication... Matilda put on around 100gm a week around that age... & she's always been a good weight gain girl, so I hope that helps. I would definately see your Dr again just to give a starting weight on Gaviscon as well. We are on our way to get a 2nd opinion this week as her reflux is getting bad again, so hopefully we might get some more answers....HTH