My DS is seven weeks old. He is fed EBM and one or two formulas a day, with a couple of short breast feeds thrown in when we feel up to it! He drinks a lot and is a big boy (almost double his birth weight!) but today he didn't feed at all from 8am onwards. He is usually awake and alert during the day, but today he was sleepy and just wanted to suck on something, so I gave him a dummy which he wouldn't let go of. At 11ish I offered him a bottle of EBM and after an hour of sucking, he'd only managed 30ml where he'd usually drain 150ml easily. I tried him again with EBM throughout the day but he didn't take anything and never requested any food at all. At 5:30pm I realised he hadn't done any wet nappies since the morning (guilt) so phoned the health visitor who recommended we go to the GP tonight. We saw the GP who said he was absolutely fine apart from the sleepiness and the non-feeding, and suggested possible thrush as a sore mouth might make him want to comfort suck and reduce his appetite. We had a prescription and came home. He still wasn't interested in the EBM but I offered him 50ml of formula which he immediately drained! He then did a small wet nappy with pink spots so I knew he was dehydrated, and he took another 100ml of formula quite happily, and then 50ml of EBM later on.
I'm happy that he's drinking again, and has done one very good wee so far, but I don't understand why he went so long without requesting food and why he's such a different boy than usual. He is my first so I have no experience of normal behaviours! Do babies have days where they're not that hungry? I feel a bit guilty that I didn't think to offer formula earlier, but he wouldn't usually have it during the day and would usually take EBM perfectly fine.