Projectile spitting up..

Sativa

My one month old son came home and used similac and parents choice formula just fine and then we switched to gerber Gentle (due to wic) and shortly after my lol started to spit up then whole bottle would just project out of his mouth. He seemed fussy and just hungry more! He eats about 4oz every 2-3 hrs (he was born at 10.4 lbs!) and that didn't seem like enough. 😫 he's just eating formula cause I didn't produce enough breast milk and just wasn't working for us, but we took him to the hospital and they tested his poopy diaper and it had blood in it so they said try soy formula. So we bought similac and parents choice soy for him until we could go to Wic and have it changed which took about a week to do and he seemed much happier fuller and wasn't spitting up full bottles anymore just like tiny bits here and there seems to slow down some and when we finally switched to Gerber soy he was fine for about a week or two and then just recently started spitting up about 2 ounces at a time and just projectile spitting up full bottles it seems. Is Gerber the issue? Does he have reflux? Is he colic? What's your mommy opinion. (Yes we made a doctor appointment)