I've had to start bottle feeding my 3 week old ...

I've had to start bottle feeding my 3 week old with thickened formula as she's so hungry. She also gets constipated. A little bit of dark brown (soft) sugar in the bottle works, but not too much too often. We're trying to get her to drink some warm water to help with her wind and constipation, but she's not too impressed with it and spits it out! Give it a try, it may work.