My wee boy is three months (14 weeks) old and has until now been exclusively breast fed. Health visitor raised concerns at 8 weeks that he wasn't gaining enough weight and suggested formula 'top up' but was happy to let me continue bf and monitor things. At 12 weeks he had a day of projectile vomiting and we spent a night in hospital; they couldn't find a cause and he seemed back to normal so he was discharged. Latest weight check this week showed he'd lost 4oz in the last fortnight.
So I've started him on 4oz formula at night on top of breastfeeding. But now he seems frustrated at the breast and it's a real struggle to get him to settle for a feed and he seems hungry all the time. On the couple of occasions I've given him expressed milk in a bottle it has taken him a couple of days to stop fussing and feed normally on the breast. It's as if he is lazy/frustrated at having to suck after getting it so easy/quickly from bottle. My concern is that if I'm giving him a bottle every day he'll not settle at boob and will continue to lose weight so I'll have to switch to fully formula fed, which I had hoped not to do until 6 or 7 months.
Any experience/advice?