It's not always something to really be concerned about, but, diarrahea is **usually** a symptom of something going awry, for all animals, young and old, including humans. But, it could be just a simple upset tummy. If she's been checked out, and gotten a clean bill of health, I would probably see if I could call and speak to the vet and mention that she has diarrhea, now (unless that was the reason you took her in to begin with, I wasn't sure if it started before or after). But, there are many things that can cause diarrahea, and, it's not always easy to figure out what she may have gotten into. Is she eating any canned food or anything else really soft? Did they give her anything at the vet? Maybe a shot or a vitamin or something? Has anything happened in the last few days that could have interrupted her routine? Stress can cause that, too. Heck, maybe even the vet visit itself stressed her out a little. You just never can really tell what's going to affect a certain dog in that way. Hope it's just a little tummy upset, and, nothing to worry about. I'd just look at the poo and make sure there's no blood or anything in it that shouldn't be there. Nasty task, but, it could be a good sign if there's anything really wrong. You could maybe try giving her some Pepto Bismol, I've heard that can help with diarrahea, although I've never given it so I don't know dosages or anything. I have made a tea for Finn once for nausea that worked like a charm, but, I don't know if it would be as effective against diarrahea.