acatsmeow. How much blood is there? If is quite a bit, then you should take her to the vet. If not, sometimes a change in their diet will cause this problem. Have you changed her food in the past month or so? When I lived in central Calif, I noticed that some of my cats had blood in their stool. But the vet told me that sometimes this willl happen when you change their diet especially when feeding them more meat/canned food.

..............wayne