Hello,
What you are seeing is called Hematochezia is the presence of bright red, fresh blood in the feces. Hematochezia usually occurs with bleeding in the lower intestines like the colon, or the rectum. This could be something minor to a more serious problem.
There are many problems that can be causing this from a protozoa infection, bacterial enteritis, Problem with the food, Polyps in the colon, an anal fissure, or even cancer. This will need to be watched and checked out by your Vet. ASAP Joan Jav917
http://www.petplace.com/cats/hematochezia-blood-in-stool-in-cats/page1.aspx
Vet. Tech
I have been a Vet, Tech. for over 30+ years. Working with Large Cats as well as house cats