Explosive poop = normal for bf baby....unfortunately. We have constanant poop up the back....
Happy spit up + small amounts = normal. My LO went through a period, around 5-6 weeks adjusted actually, where he spit up every day, but it was happy spit up. I think he was eating a tad too much. When I first started feeding him bottles of expressed milk, I overfed him and got projectile vomit.