Cat with Blood in stool

Question
I have 2 cats that I have had for 2 1/2 years.  

Tonight, we had a birthday party for our daughter and discovered that my female cat defecated in my bathroom.  I am convinced it was my female as she is not a people person and spends most of the time hiding when I have company.  Upon discovering the feces, there was a fair amount of bright red blood in her feces.  She is about 3 years old and was spayed about 2 years ago.  

She has not lost her appetite and seems to drink plenty, she will come out and "demand" her attention once the children have gone to bed, she and the male cat still play constantly.  Over all, I have not noticed a change in her personality.

I am also wondering if this is something contagious and should I be concerned about the other cat.

Answer
Traci,

If the bloody diarrhea continues, I would recommend taking your cat to the veterinarian for a check up.  Normally this type of colitis is not contagious to other cats but you can never know for sure.  I have found that high anxiety cats can have seriously upset tummies when they are stressed.  If the diarrhea has resolved, I would recommend watching her next time there are people over and see if there is a trend.

Good luck to you both