Hi My Daughter Is 3months And Was In The Hospital

Hi my daughter is 3months and was in the hospital because of a urine infection and rhino virus before that they changed her milk to nutramigen and was pooping good now since we left the hospital she has mucus in her stool and today I started to notice a little bit of blood and she also has a rash should I be concerned her doctor said the mucus was normal because of the antibiotics