formula issues

[melfy77]

DS is 5 weeks old and gets both breastmilk (day) and formula (night), althought we often mix both. She doesn't drink a lot (2 oz every 2-3 hours) during the day and a little more at night, but not always. She is very gassy and fussy, and she obviously has bad gas pain. We switched to Dr Brown's bottles. it help a little with burping, but after pretty much every feed, her face turns red, she tenses up with pain and cries. It lasts for a few minutes, then stops. Same thing when she sleeps. She`s not constipated (poo is green and soft), but she farts a lot, and it really smells. She's on Nestle good start (regular one). For the pas 2-3 days, she's been throwing up 2-3 times during the feed, when there's formula in the bottle. I called my ped but she won't be there until next week . I'm starting to think maybe the formula doesn't work for her, but there's sooo many formulas out there!!!