The first thing is not to get overly worried (easy for me to say, right?) as this is a common condition for many Frenchie puppies which have just been placed in their new forever homes (although very few of the Frenchie puppies we have placed have shown any of these symptoms). All of our puppies have been given age appropriate DAPP vaccinations (at 6 weeks & 9 weeks of age, and at 12 weeks if you buy an older puppy), along with at least the 1st Bordetella vaccination at 9 weeks, so their chance of having something serious like Parvo is virtually zero, and our guarantee would cover this disease if it were to ever occur in a puppy we place in its new home.
Our puppies have also been given preventive medications for worms, Giardia, and Coccidia, which can all cause the types of symptoms mentioned above. Puppies are considered high risk for Giardia and Coccidia, as well as other intestinal bacteria and parasites, and preventive medications are no guarantee that none of these conditions will appear. They are often brought on by the stress of shipping, a new home and environment, a diet change, new people and playmates, a change in climate, etc. Blood in the stool can also be brought on by a puppy eating something he/she should not have eaten, and Frenchie puppies are just like human babies – everything they find goes into their mouths.
Fortunately, none of these conditions are serious and can be easily treated. You should be taking your new Frenchie puppy to a qualified vet within 30 days so that your guarantee will not be voided, and in the event that your puppy has a problem with his/her stool, your vet can prescribe medication to take care of the problem with no long term ill effects.