If your doctor has NFI about what's going on, then you'll need to speak to someone else. Even if it is reflux, then you need to know that a) you're on the right treatment plan and b) if you're medicating, that you're using the right doseage! It won't work if you don't.

Often, these mysteries are easily resolved as soon as you speak to someone who actually knows what they're on about. Call an LC. They can rule out a number of possible feeding issues and point you in the right direction if there's an underlying medical problem.

Oh, last question, did your DD2 get the rotavirus vax and did it get worse after that?