The first thing that I would check with Kalypso is that she is well hydrated. She'll be losing a lot of water in her diarrhoea that would normally be absorbed in the intestine, and being dehydrated can be quite dangerous.

There can be many causes for blood in the faeces, but it certainly is not a good sign and I would advise that a trip to the vet is in order to identify the problem exactly. Whilst I was on work experience at the vet practice, we had a cat in exhibiting loose faeces with blood which was identified with a gastrointestinal condition, so this could be what Kalypso has got too.

I'm so sorry that Kalypso is under the weather. I hope she'll be feeling a lot better soon!