Commonly prescribed motility drugs for infants include Reglan (metoclopramide) and erythromycin, and here in Canada we can also get Motilium (domperidone) which my daughter is currently on. Not sure if you can get that in the US though. Reglan can be controversial because of potential side effects in infants and children, but I know a few moms on here have mentioned using erythromycin for their little ones.
So sorry to hear you and Brielle are having as tough a time as ever. So are we, and it can be so discouraging when you are hoping for them to hurry up and outgrow it! Hang in there, and try to take it one day at a time. Good luck!