Suzi has vomited all night long and has had diarreah.

SHe has never been this ill in her life. She's 9 months old and about 8 1/2 lbs. Anther huge scare is that their has been droplets of blood on her pads coming from when she has poo.
I called the vet amd was we have an appoiontment, however it is not until 4 this afternoon. Suzi stays inside , and never too far away from us.
What can cause a sudden tummy trouble so fast? And cause all these problems? I am scared for her. She is behaving ok, not lethargic or anything. The vet office won't tell me anything. Suzi has stopped vomiting and the last time she did it was spit up. But, she is having the runs a little bit still.
I was told not t o let her eat anything and to keep her calm.. Does anyone have any ideas ?