Bloody mucus after enema?

My cat, Pepper, has been experiencing problems with constipation due to severe arthritis in her left rear leg. She was so blocked up that she had an enema today. I just found bloody mucus on the floor but I have 3 cats and can't figure out who it came from (all 3 have had various health issues lately). I smelled it (TMI I know) and it doesn't have an anal smell. It smells kinda like snot. What should I do?

I called my on-call vet last night after posting this. Apparently she was so constipated that it was rough on her intestines while coming out. The mucus meant inflammation. And it hasn't happened since last night, so we're in the clear. Now if we can just get her regular, we'll be doing great!

I know the feeling when you have multiple cats and aren't sure which one has the problem.  I'm glad your vet was able to answer your concerns. 

Have you ever tried giving her pumpkin for the constipation?  You might want to talk to your vet about that.