Pooping on the bed, peeing outside the box - separation anxiety?

Hello, all. I've got a cat mystery on my hands...

Last week, my roommate got a new chair. For a day or so, all was fine, but after we rearranged the living room and my room - both to accommodate the chair and because we'd been meaning to move things around for some time - my roommate returned home to find that one of my two cats had peed all over the new chair. 

I rushed home and did what I always do for cat pee - the home cure of vinegar/water, then baking soda, then peroxide/dish soap, let dry, and vacuum up. I thought all would be fine, but when I got back from a long outing the NEXT day, I found poop just outside the bathroom (where the litter box is) AND pee all over the chair.

I was working from home all the following day - no incidents. But tonight, my roommate and I got back and there was poop ON MY BED and a puddle of pee by one of the bookcases in my living room.

Some history: I have two kitties. One, Keila, I adopted from the Humane Society of San Diego in 2006 when she was a year old. The second, Ishi, was rescued by a friend of mine (along with her mom and sibs) and I adopted her when she was 8 weeks old (this was in 2010). Keila was fixed when I adopted her, but I had to wait to get Ishi fixed until last year because of work. A few months before I had her fixed, she definitely had a problem with peeing - especially on my bed.

The two cats are not exactly friends, but they're not enemies. They don't snuggle or cuddle, but they do sniff each other and chase. Ishi is bigger than Keila now, and much more demanding of attention. Keila, however, hates when I leave the house. She will run up to the door and "block" me from leaving by getting up on her hinders and putting her paws on the door, howling. I generally pet her a little and talk to her and then leave.

Since the furniture move, Ishi has been pestering me a little bit more for attention. Other than that, both cats are acting normal. They're eating and drinking, cuddling with me, running around, and so on.

So: someone needs to go to the vet. But: which cat? And: what is causing this behavior? Was it the rearranging, my leaving, or what? The only clue I have is that Ishi walked over to the puddle of pee by the bookcase and began to try and "cover" it by scratching at the carpet. Does this mean it's mostly likely HER pee?

Hiya! Not sure over who's pee it is - my cat tries to cover other animals poop when we are on a walk, even dogs! I just guess he's trying to tidy up '-)

There's a few things here. Peeing outside the box may be a sign of a UTI, so may be worth a trip to the vet to rule that out. Maybe too it's worth seeing if there is anything for your cat that doesn't like you leaving to help calm kitty. Feliway may help you here too, tho it's rather expensive. 

It does sound more stress related tho than illness. Some cats really don't like change, so rearranging the furniture may have caused some distress.  Also, have you had a sniff of the chair itself? Perhaps it has a strange smell, a factory smell or something which the cats may like to pee over.  To try and stop that you could rub their blanket or something over it so it smells of them, and another trick is to place some cat treats on and around it, cat's think twice about peeing on their food... 

My cat would pee wherever catnip had been, ie, I knocked over a small dish of catnip and didn't hoover it immediately and found my cat sprayed on that area. It happened twice, so am guessing he had a thing about catnip and it was irresistible! I am wondering if the chair has something similar about it.

Am not sure about the poop as never had to deal with that.  Perhaps trying a couple of new litter trays may help - sometimes cat's like more than one, or one for pee and one for poop. Perhaps putting one in your bedroom may help out?

Sorry am not much help, just thinking aloud really. Hope you manage to find something that helps soon, it's not so nice having to deal with that. Good luck.

I have a cat who misses the litter box on occassion, I also have a cat who tries to bury the other cats misses, so thats not necessarily the culprit.  I agree that a vet visit is in order.  Is there any way you could separate them for a day or so to see which one misses the box?