Bulldogs World

Because Molly came down with diarrhea again late Monday night.  I posted almost a month ago exactly because she had a bad case of it where she was going every couple of hours and it was basically water.  This time was not so bad.  She just went twice over 7 hours, but I'm still frustrated that it is happening again and don't know why! They tested a stool sample and it is negative.  The vet said she probably just has a sensitive stomach, put her on a bland diet and bring her in if it doesn't go away in a day or two.  I also have some flagyl left over, but only 3 days worth, so I started her on that.  She seems to be doing well on the bland food. 

I only have 1 theory and was wondering your opinions! I took her to the dog park on Saturday (which I rarely do) and the first dog she approached unfortunately snapped at her.  After that she was drooling heavily and isolated herself, which I assumed was her nerves (the weather was cool). After about 5-10 minutes though, she was over it and played with the other dogs and the drooling stopped.  Do you think this one incident could have stressed her and caused an upset stomach? She is generally a nervous dog with new situations, but I don't know if it would cause diarrhea 2 days later!  Any opinions would be greatly appreciated! I hate seeing her sick :(