If he's drinking alot of water he's gonna pee alot. Plus puppies really don't have much control over their bowels or bladder until they are about 12 weeks or older. Keep in mind his bladder is very tiny and can't hold much for long.

What's probably happening is that the breeder was feeding a different kind of dog food and the abrupt change upset his little tummy. OR it could be Giardia or coccidia. You need to take him to the vet and get a stool sample just to be sure. Both of t...