cat does OK with new kitten but there's a problem

Hi, I'm new to the boards here, and I have a perplexing question about my cats. I have a two-year-old cat, Cocoa, and just got a three-month-old kitten, Linus, a few weeks ago. They've been gradually spending more time together and are doing OK, mostly playing and a little bit of growling on Cocoa's part, but I've noticed a problem.

They have separate litter boxes for now, although sometimes Linus uses Cocoa's box anyway, and a few times, Cocoa has gone in her litter box to use it, and does use it, but she doesn't relieve herself all the way--I don't know any other way to put it--some of the waste is still protruding when she exits the box, and she scoots across the living room floor on her rear end. What in the world?!

Have any of you experienced a similar problem when introducing a cat to a kitten? I'd appreciate advice--I hope Cocoa will stop doing this, because it's not good for anyone.

Thank you!!

I don't think this is something she would do on purpose. Is she constipated, is something chasing her out before she is finished? I've had cats do this on occasion, and for some reason, the whole thing didn't come out, making for a chase from me, trying to get it before it ends up shmeared on the floor.
Maybe you should add a little oil to her diet. Maybe her "bowel's are in an uproar".

OK. Thanks so much for the advice--what kind of oil? Olive oil, maybe?

I don't think anything is chasing her out--I haven't noticed Linus trying to shoo her out of the litter box or anything like that.

I haven't changed Cocoa's diet any, and she's on good-quality cat food, but one thing I wonder is if it might be nerves--nerves can lead to these kinds of problems.

The vet should look at her for anal gland problems.