A little more details would be helpful to those trying give you advice.
From just what you have here, it sounds like your puppy may just have an upset tummy.. or got into something? Is he vomitting too? Drinking water? Eating? how's his energy?
I would still take a sample for stool to the vet for testing just in case.
Commander Charly Titan (GSD)-15 Jan 2010
Lady Athena (BB)-2011-2012 (RIP baby girl)