Hi there,
We used Neocate, which is basically the same thing as the Elecare. My lo would drink about 35 ounces/day on the Nutramigen at 3 months, but when we switched her over, she didn’t drink as much either. For one thing, it has a different taste that the babies don’t like too much, but hten they get used to it normally after a little while. Also, once they’re getting relief from their medication and the good formula helping to make their tummies feel better, often they don’t drink as much either. Some babies (like mine) was a soothing eater–her tummy/throat her, so drinking all that formula feels good going down, but once they’re feeling better, they don’t need to make it feel better!
How old is your lo? Is he on any meds for the reflux?
Hope this helps and good luck!