HELP!

Mariele has always spit up slightly more than the average baby. I say this after having Analese, who I can probably count on my hands the number of times she ever spit up. After having Analese I thought, "What is up with these burp rags? Does anyone actually NEED these?" But Mariele is a whole different story. Our ped has already diagnosed her with GERD/Reflux, but we are not doing any meds yet. My instructions have just been to keep her upright after feedings. Well, this morning she was sitting in the kitchen in her bouncy chair watching me and Analese get some breakfast when she suddenly projectile vomited the entire contents of her stomach. This was not a normal spit up, it was a geyser. Then she had her daily morning poo blow-out. So the kid cleared her entire digestive tract in the space of a couple of minutes. She was then a little fussy, probably because I removed all her clothing right then and there. I also had spit-up and poo all over me, so we took a bath together. She LOVES a bath. It really does make her happy to feel the warm water on her belly. I now have her dressed in a clean pair of jammies and I have her swaddled. She nursed a little and is now sleeping in my arms. I know some of you have had GERD/Reflux diagnoses for your little ones. Any advice that you can give me? Anyone experience very large projectile vomits from their little ones?