Thanks for the support. Rebecca77 in response to your questions I am thickening his formula with Karicare thickener. He is still gaining weight at an average rate. I keep telling myself to stop stressing as he is gaining weight, wetting 6-8 nappies a day and is doing a poo every day. But I can't help worrying. He does seem to be a bit happier today but still will only drink about 80 mls each feed. He should be drinking 120 but he just doesn't want it. I'm not sure if I can give him Mariners infant mixture or Brauers colic relief as he is already on Zantac.