Is this normal? Breast/Ff baby

So I breastfeed and I’ll give maybe 2 bottles of formula a day, my baby is one month old and he used to poop a lot more but now only poops like once a day. And it seems a little fussy/difficult for him and then he explodes diarrhea.

I know breastfed babies poop is more watery and yellowish but is this normal?