Can a baby become intolerant to formula overnight?

[Librashavinganotherbiscuit]

DD is 5 months, since she was 6 weeks old her 10pm feed has been formula, all other feeds are breastmilk. For the last week about 10mins after she has finished her feed (somewhere between 3-6oz) she starts coughing and then throws about half (maybe more) back up, this isn't the usual posseting amount. She has got a cough and just getting over chickenpox but she doesn't throw any of her day feeds back up (apart from slight posseting), the only thing i can think of is her tummy doesn't like formula - but she has been having it for over 3 months with no problems!
Any suggestions?

A doctor told me that they can develop a temporary intolerance if they've been unwell but that if you take it away for a few weeks they get over it. That was when my 17 year old godson was a baby so maybe a word with your health visitor to double check would be a good idea?

My eff DD occassionally throws up her 10pm feed when she has a cold/cough. I think it is to do with lying down after feeding and being full of snot. DD certainly is not intolerant of formula. I guess you could experiment with switching that feed to EBM or which feed is formula to see (if that is possible for you, not sure as don't BF, so I don't know about the practicalities of this).

My friend's baby developed secondary lactose intolerance after an upset stomach so had to have hypoallergenic formula until she got better. V&D bugs can damage the stomach lining which causes the problem. I don't know about other sorts of illness.

Thanks for all the replies, not sure whether to perservere (she doesn't seem to be in any pain or even mind when she throws up) or give up for a week and risk her refusing a bottle when we retry formula.

As it sounds from the other responses it could be a temporary thing, I just wanted to offer reassurance that if you were to switch the bedtime feed back to a breastfeed for a while that would work, (in the sense that your milk supply will cope with this easily) and you could try her on a bottle of formula again in a few weeks.

Bottle refusal can happen even if they're used to having one - there's not much you can do to influence it, so don't worry :)

maybe she is just taking too much? it's far easier to drink from a bottle than from breast so maybe just taking more than she can handle?

doesn't sound like an intolerance to me, sorry

would agree iwth just doing a breastfeeed instead btw

is there a particular reason you want her to have formula/bottle?

I did b/f her last night after she threw up the formula and whilst I agree babies can bottle refuse at any time they are less likely to do it whilst having a bottle a day which is what she has had since 6 weeks.

The reason I am still b/f at all at 5 months is because she has a bottle of formula at 10pm. I need that break and the ability to have a social life (hahahahaha) if I want.

I agree it's not likely to be a sudden intolerance was clutching at straws to work out what was wrong!! Thank you for all your replies, am going to breastfeed only tonight and see what happens (i.e. if she is sick or not)