pyloric stenosis or??

My son just turned 4 months and since birth he don't ever keep nothing down... I have been back and forth with doctors and G.I. specialist... then he had a exam done by like a cat scan watching where the milk goes down.. it was going to his lungs so they just put him on a thickener to mix with his formula and a acid reflex medicine but he's still vomiting and nothing is changing and it can happen like 5 times after he has already ate or puked .. it just pours out out of him .... this has been a non stop battle but all the doctors are saying he will be fine and eventually grow out of it because he's not losing weight..

What did it take or happen or the cause of surgery for your baby... or did your baby out grow this??