I would say he has reflux - sounds pretty similar to what my DD2 was doing.

FWIW, i've read that lactose intolerance in babies shows as coming out the other end in great waves, not puking

We tried DD2 on a lactose free formula, made NO difference to her puking whatsoever. We tried EVERY formula to try and stop the vomiting, tried infant gaviscon for the reflux pain (cos she would scream during and after feeds) and that helped a little. When she was 3 months we took her off the gaviscon, and she is much better now. She doesn't scream, she still vomits - but its nothing compared to what it used to be.

I wouldn't personally try a different formula, because it probably won't make a difference. We have her on Heinz Nurture now, cos we figured if all of them have the same effect, then we aren't going to spend $30 on a tin, when we can spend $17 or something like that.. LOL

But yes, as she gets older she gets better. I was advised to try the normal things to help reflux babies - sleep them on an incline, sit them up for 20 minutes after a feed, feed them sorta sitting up instead of laying back in your arms etc. The only thing we didn't do was sleep on an incline, we have her on her belly, she sleeps better that way and we think it soothed her belly pains. However, she does vomit and then roll her head in it which is grosssss.