Clear Spitup

Am

Hey guys!! I’ve been combo feeding my baby for the last couple of weeks. We feed similac pro advance during the day while I’m at work and in the morning and evening I nurse. For the last few days my baby has been spitting up clear fluids with tiny tiny curds and then his poop is really really really runny. Anyone have experience with this? He’s chubby as all get out and the happiest baby. He is still super alert and having plenty wet diapers so I’m not worried about dehydration just wondering if this is normal?? I also have to stop and burp him after just a few minutes like 2 and he just screams until he finally burps both nursing and bottle feeding . That part is miserable.