Hmm I'm not sure Charlotte, but could she have reflux? could that formula not be agreeing with her, perhaps a new one needs to be tried? I'm sorry I don't know much about Gastroschisis either. Just thought I'd offer some advice anyway.

I hope you can get some answers soon, have you booked in with the GP or local MCHN to see them perhaps?

Also, in regards to solids, she won't really be ready for solids until she's at least 5-6mths of age. That is the recommended age, approx 6mths for babies to be introduced to solids. Anytime before that, a baby may not be ready as they have a really immature digestive system hence milk (breastmilk or formula) is only needed in the first 6mths.

I hope I've helped somewhat.