My ds was breastfed for 5 weeks and now FF. Anyway last 2 days he has stopped being interested in feeding. I feed on demand, and he was eating 3-5oz anything from 2-4 hours apart. He has been diagnosed with reflux as he was vomiting so much (this started when breastfed). now he will make hunger signs, I will try and feed him and he will either scream and turn head away or suck a couple of times and then fall asleep.
Generally he is a poor sleeper, but has suddenly started sleeping most of the day. Even if it has been 4 hours he will only take 1oz and then either go back to sleep or scream.
I have tried waking him up, changing nappy etc but he either refuses or screams hysterically, with real tears!
Firstly could you change formula and see if it makes a difference. Also, have you been given anything to help with the reflux?
You really need to take him to see the GP if he's not taking enough feed or his weight will drop off too much but also you could ask to have tested for lactose intolerance - especially if he was like it bf as well.
My friend's DD had lactose intolerance and wouldn't stop being sick and was given soya milk and she was then fine. Not saying it could be that but it's another thing to ask GP about. You don't want a 5 week old not feeding; you're already so upset. Try feeding him little and often and see if that makes a difference - him only taking an oz every 4 hours is worrying. Could you take him today to an out of hours doctor as he isn't taking his feeds? What are nappies like? Are you having lots of wet nappies?