My son was on Similac Pro Advance from the hospital til 2 days ago. He is 2 weeks old. We switched him to Similac Pro Sensitive because he was having runny poops every time he ate and it was so acidic that it was giving him an awful diaper rash that couldn’t go away bc of how often he was pooping. But the main reason I switched was because the one time it looked like a strand of blood was in his poop from so I thought maybe lactose allergy? Now the sensitive it seems like he’s not pooping barely at all.. he’s had one BM since we started him on it almost 2 days ago. I’m reading places that it’s common with the sensitive. But he also seems a lil more fussy between feedings like he might be gassy. Should we keep trying the sensitive? Switch back to advance? Or try a different brand (was gonna try Enfamil) please give me some advice:)