When is the spitting up considered reflux??

[cm.thomas]

DS is 4 wks old and spits up like I've never seen. It just flows out after feedings and at all times in between. On top of that, he's super fussy right before he spits up and it's becoming increasingly worse especially at night. He's been really agitated and uncomfortable and can't relax. All he wants to do is nurse (my guess is because it feels better to be eating).

So I know my son is not comfortable, I've already taken dairy out of my diet and what I'm hearing from our midwife (ds is under her care until 6 wks old ) is he's taking in too much air, he's probably eating too much at a feeding, try keeping him upright after feeding etc. I KNOW these things! DS #1 spit up like crazy too, the only difference is DS #1 wasn't in pain because of it. He was a happy spitter.

Sooo...does this sound like reflux?? do I take ds to the pedi and get a second opinion? I just don't want to hear the same things again... I want my baby to feel better...yesterday!!