Bloody mucus in stool

Just as Trink is about to go to the vet (x-rays tomorrow) and hopefully be all better, I see bloody mucus in her poop. Her poop is also a little loose but formed. It stinks horribly.
I’m upset. I am feeding them a huge variety of Fancy Feast – maybe that’s contributing the the smelly poop – maybe I need to stick to a few kinds at a time? I’ve had this happen (the bloody mucus poop) with other cats and I don’t think it was necessarily a huge deal, but I don’t remember exactly.

What do you think? Does anyone have any experience with this?

 

I have had this occasionally in both of my cats. It scared to poop out of me! I rushed my cat Sadie in after seeing that once....the vet said sometimes stress can cause it and gave me pro pectin...but I'd say its better to play it safe and take a trip to the vet if possible.