If my daughter has a protein allergy and is on alimentum similac . Do you think she would have a…

If my daughter has a protein allergy and is on alimentum similac . Do you think she would have a protein intolerance to foods and making her have diarrhea ? She has had bad diarrhea for about 2 weeks the first time we went to the doctor they said it was her teething . Now we are going again Wednesday because I’ve seen no change . Just looking for opinions??