I don't know what else to do guys...

My 3 week old cries during and after feedings. Tries to poop constantly during feedings. He poots and poops, so I don't know if that's the problem. Poop has been yellow, it was green today, with a peanut butter/paste consistency.

He also arches his back and gets really stiff in the middle of feedings, so I called his doctor and she called him in some acid reflux medicine. He spit it out😭. Next time I'll put it in his bottle. We're trying this out to see if it's silent reflux since he doesn't really spit up.

Anyone else going through this?