No-one on here is going to be able to diagose what is wrong with your dog with the symptoms you give. We dont know the dogs history, his age, etc.
However, if he has been sick, has diahroah and generally unwell I would suggest you get him to the vets asap............if it were me, I would have called the emergency vet today as he could be getting severely dehydrated at this stage, and could have a soaring temperature which is a danger in itself.
Hope he is ok, keep us posted.