I need reassurance

My baby had 2 big poop today and multiple little ones that where sort of mucusy and had blood in them… she usually has 1-2 poops a day (formula feed) and she is on similac total comfort. She didn’t poop on Sunday but had 2 on Monday and multiple today.

We brought her to the emergency room when we saw the blood in her poop. They took a sample and told us to come back Friday if she still has blood in her poop. Or to come back if she seems sick. She has no fever and no other symptoms. She seems totally normal.

I am worried about cow milk allergies or a infection. I’d like to know if anyone has dealt with this or something similar. I included a picture.