My baby (4mo) has diarrhea after her rota virus injection, is it normal ? When should I go and see the doctor ? She is not cranky or restless but just act as per normal except that she poo often and its watery. TIA

Yes, mild diarrhea is a common side effect for this vaccine. You need not worry unless you notice your baby having these signs: abdominal pain, bloody stools (or passing a redcurrant jelly), or starts vomiting. In which case, medical attention is required.