[Ellie May]

I'm sure you already know that diarrhea (particularly that much) in a five week old can very easily lead to death. There isn't anything that should be tried at home. He should go to the vet immediately. I'm not sure if that is possible or not, but it is what is needed. He is likely extremely dehydrated by now.

You can try something at home like Pedialyte, bland diet, etc. but that isn't a replacement for veterinary care and it is absolutely not safe.

I'm guessing things like parvo virus are a concern over there too just like here.