baby with poor appetite

Hello my little abigail has had reflux since she was born, she has never had a good appitie, never really cried much for food, she is fully weaned and at first after changing to omperazole she ate quite well, now however its a battle to get her to eat, she is happy in herself and does not seem in that much pain, but she neither craves food nor accpets much of it, she will only dream feed milk at night, will not think of it in the day, any suggestions or simular experience, thanks