Hi there, my 5 month old is doing the exact same thing, but has done on and off since birth, which has been really frustrating and stressful. For a couple of days he will drink all bottles, and then for a week he will refuse most bottles and only take in a fraction of what he should be drinking but strangely is still content with this, apart from when I try and make him drink, then he pokes his tongue out, chews of the teat, turns his head or throws himself back and gets cranky. He is on reflux med's but still does this. There is no consistency with his drinking and it drives me nuts, fortunately he's a fantastic sleeper. Any other ideas? He has put on weight steadily apart from this month where he put on none at all, and mostly has wet nappies...... help!