You should talk to your public health nurse, GP or pharmacist before switching the baby’s feed. I’m in the same boat myself. My son is 6 wks, over 12lbs now and feeding like crazy! He’s in 3-6 months clothes already! I am supplementing his breastfeeding with formula as he was latched on every 30 mins giving me little or no sleep each night…anyway, the formula seemed to be working great until he only got 2hrs instead of the normal 4 hrs after guzzling 7-8oz…
so i was putting him on the next formula for hungry babies and my midwife said to be careful. When you put them on a hungrier formula, it’s harder for them to digest and it might make them irritable. Her advise to me was to give him 2-3oz of tepid boiled water before a feed and it’s worked a treat! And if the water doesn’t work and your doc says to move to the next stage, you’ll be grand. Good luck!