Baby’s poo dark green milk allergy or temp lactose ?

[Dbf123]

Hi baby been really unsettled last few days on hipp formula then she was constipated for a couple of days also she was a little be rashy on her face the. She’s finally had a poo and it’s dark green I switched her to comfort formula yesterday and she was a lot more settled but I don’t no how long it will last ?

That needs a warning in your title.

The range of colours for small baby poo is pretty wide, except for persistent very pale stools or evidence of blood I'd be pretty relaxed that there is unlikely to be a specific medical reason for a poo that looked like that.