Dr Katie Heathershaw (or any of the Paed's at Melbourne Childrens Clinic) in Camberwell. I've seen her for my son & daughter (separate problems), she is fantastic, very thorough, trusts mothers instincts, and actually listens to what you have to say before she forms her opinion. They also have a whole team of other health professionals (gastro, surgeons, dieiticians etc), which has been great as they all talk to each other.