It's not too strange, when it comes to our pets, to worry about anything. Especially something that has never happened before "BUT...IT HAS NEVER HAPPENED BEFORE!" - worries us. Doesn't it? Does this make it more reasonable to worry? Maybe, but if you apply rational thinking, after slowing down your thinking for a while, does your worry MEAN what the puppy's currently having is more dangerous than anything else? No, you're worried - and that's it. Of course, it doesn't mean it is harmless, either.
Just employ the same way of thinking as you would with a human. If you can think of a natural explanation of the diarhea dogs - do you really need to get bruised up or stressed? If you know it's been eating something that is novel to its bowel, you can probably calm down.
Some other things - that you could probably guess were causes, but which I will mention for your convenience - are if the puppy's been stressed or excited. A thing that could trigger those two emotional states, are when it has been gone from home, and then returns.
Of course, however, if the diarrhea's going on for a long time - like weeks rather than days - and if the diarrhea's not controlled, or comes in liquid-form, that is something different entirely. You will want to avoid, at all, costs that the puppy gets dehydrated. That is very dangerous, and can happen quicker than you might think.
But let's get very rational, for a minute. Let us say your puppy's showing bad symptoms. What can you do? The vet's going to be asked to give you a diarrhea-sheet, if you're smart. Home-treatment can be used, but never for anything but milder forms of the disease - because you never ever want to risk that the dog gets dehydrated (which might happen if the diarrhea's left to go on or if it's very bad).


Hopefully this little diarhea dogs article has given you something of value. What is, in my opinion, more important than just getting the facts - are things that make you realize that  worrying about the dog's current state is most likely a waste of time, and pointless; because, probably, what is happening is not dangerous but simply a natural consequence of some form of change/stress. So, that is something to keep in mind, whenever dealing with dogs,