A.B.
I traveled to Hawaii when my first child was just 5 months old. I was exclusively breastfeeding, so I had to pump & store prior to the trip (he did not go with me) and then pump while I was there (including in-flight). I had the Medela Pump in Style backpack pump, and I brought it with me on the plane. To be honest, I can't remember what the protocol was through security, but I did bring it on the plane. I used the battery adapter and pumped in the bathroom on the plane. Definitely not the most ideal situation, but I've learned that you do what you gotta do :) I also pumped in airport bathrooms. I chose to pump and dump, rather than bringing the milk back with me. I was told by my lactation consultant at that time, that I would have had to store it for the week and then pay to have it shipped back home on dry ice. The good news, I will share, is that while my son was bottlefed (breastmilk) the week I was away, he went right back to the breast upon my return. That was something I was not sure would happen. Hope this info helps and good luck!
A.