Milk allergy or intolerance? (Poop pic)

My son is formula fed, Enfamil Gentlease which is high in iron so his poop is usually a dark green color. This was his poop today.

Things to consider:

- he had his first try at dairy Monday but was stopped after first bottle because he was extremely fussy, gassed and constipated. Yes I know constipation is common when switching.

- has had a stomach bug since Monday afternoon and he’s just getting over it

- almost 12 months old

Could he be reacting to the cows milk or just getting over the tummy bug? Or both?

Edit to add: I will be consulting his doctor on Monday. I also gave him dairy before he got a stomach bug and it wasn’t known that he had a stomach bug.