My little one is 3 weeks old. The last time she had a poo was early Thursday morning. It's now Sunday. She's was fed with SMA and some expressed breast milk but we switched on Saturday to cow and gate comfort as she had lots of wind, lactose spots and previously had green poo. The comfort milk is meant to relieve constipation in her but she still hasn't done a poo!! I know fb babies can go a while without a poo but she's more bottle than breast.