DD (2.2) was diagnosed with tonsillitis late yesterday. She was prescribed penicillin. However, since staring taking this she has now developed diarrhoea :-( I know this is a possible side effect of penicillin. Does anyone know if this is likely to go on through the whole 10 day course? If so, should I try and get a different prescription? Or give it a bit longer to see if the diarrhoea settles down? I feel terrible that the medicine that is supposed to be helping her is now making her ill in a different way. I can't let her have diarrhoea for 10 days, as it is also affecting her eating and she would be utterly miserable. Any advice?