hi -
it definitely can be reflux – if so it sounds like severe reflux. reflux can be mild (not ever entering the mouth) or severe - spitting up large amounts after feeds, projectile vomiting, spit up coming through the nose, frequent waking at night (eg every 30 min-1 hour and wanting to feed more during that time), choking at night or laying down, etc
you can do a "24 hour ph probe" where a tube in placed down the nose and measure the severity of reflux. I’d recommend that the doctor give you something (either suggestions that may help or medication. If the doctor says something like “let’s wait and see” or “it’ll pass” I’d insist on something. Maybe keep a record of how often it occurs, when it occurs, how much spit up/vomit occurs, how often he wakes up at night, etc and take that info to the doctor
more info: http://digestive.niddk.nih.gov/ddiseases/pubs/gerdinfant/
Good luck!