is there anything I can give a 2 year old for diarrhea?

[hopful]

Is it worth me taking a trip to the chemist? He is in pain with tummy ache but has already had calpol

no, they can't have anything really. Keep up fluids and maybe give something like dioralyte

Dioralyte which you can buy from the chemist. You can get flavoured ones. Keep the fluids up as much as you can.