What Could Be Wrong If A Dog Has Blood In Stools Dog Is Throwing Up And Having Loose Stool--what's Wrong?

Dog is throwing up and having loose stool--what's wrong? - what could be wrong if a dog has blood in stools

I have a 9-year-old chow / shih-tzu female who is afraid of thunder. Well, yesterday we had a thunder and seemed shocked - usually no vomiting or loose stools when frightened or scared. The thunder stopped by 5 clock and 10:30 clock, my dog acted as if they really needed to leave. So I picked up and had loose stools in two places. Then at 12:30 Clock I have to get out again and she again had loose stools in two places. She did not start throwing until morning.
To make a long story short --- I value your time and seems to be, vomiting and diarrhea every 3-4 hours. The chair last thing I had was a light yellow, viscous, and had a little blood in it.
A week ago we noticed that my cat had been exhausted ()dismissed an accident in the house and with a little blood, so I thought I could be the flu that happened animal to animal.
Have you any idea what might be going on with my dog? Thank you.