Poop question!

rubber_chicken

My 5 month old is exclusively fed breastmilk in a bottle (never got her to latch).  For the first months her poop was yellow, seedy and didn't smell.

But in the last couple weeks, her poop started to get stinky.  Kind of sour smelling.  It's also getting darker, sometimes brownish, sometimes greenish. She's not having any symptoms of being sick - no fever, or fussiness, or diarrhea or constipation.

Has anyone else's baby gone through something similar? Is this normal or is it something to call the doctor about?