Formula and poops - Help!!

Had my little man, Ruairí, April 24. He’ll be 5 wks on Tuesday. He is pretty good baby, but very fussy in the evenings and he poops at every single bottle. Every poop like green and yellow and grainy. I though maybe it was the formula I was using. But have not been able to find a new one that suits him.

This is a bit long winded but please bare with me...

I have a few questions;

When u change formula to a new one, how long is it before you think it’s working or not?

Are the grainy poops ok?

I have gone back to the old formula every time as he seems to be taking it the best, still fussy and grainy poops.

HELP!!!

I have tried...

Enfamil A+ (this is the original formula I go back to every time) grainy poop and fussy evenings and a little in the morning.

Enfamil A+ Lactose Free - very very fussy on this one no pooping at all.

Similac Sensitive - spit up lots on this one and poops didn’t change last 2 days on it.

Good start - probiotic - spit up lots on this one and poops didn’t change last 2 days on it.

Similac Alimentum - drank 2 oz and refused any more.