Hi! FTM here. I just went back to work this week (8w PP). My son is abeing watched by his grandparents which is so fun! I have a good freezer stash going and took my first milk brick (from December when he was 2w old) with him so that the oldest milk is getting used first. And suddenly all he’s done is poop the last two days. 8 poopy diapers yesterday! And he’s getting a horrible diaper rash.

Is it possible his stomach is reacting to the milk from when he was younger? Or am I eating something that he’s suddenly reacting to? (I have not had any dietary changes).