Sudden feces elimination on dining room floor, HELP!

Greetings,

We have a British Longhair female cat (Angel) that is almost 4 years old. About two weeks ago, she had a loose stool episode on the carpeted dining room floor. The very next day, she had another episode again on the dining room floor near the first one. The second time it was the healthy tootsie roll kind which is her normal. Then it was a third the next day.
We took her to the vet and her stool sample was clear. They told us since her litter box is upstairs to keep her confined to the second floor for a few days hoping she goes back in the litter box. Well, she did fine for a few days and used her box everytime
Yesturday we let her have roam of the house again, and wouldn't you know it, another elimination in the dining room!!
At this point she is NOT urinating on the floor and using her litter box for that. We have sprayed the area where she has "pooped" with the enzyme cleaner like we are supposed to.
Her diet has not changed and there have been no new changes in the household. No new cat litter as well (we use pure pine pellets)
One thing of note. Angel hurt her paw while playing (about 2 months ago) and has developed a bit of a limp. The vet has taken x-rays and feels that it is just inflamation. He also said the area needs to be watched so that it does not grow (hopefully not a tumor or anything) The vet gave her a shot of anti-inflamation medication which only helped for about a week. He said the shot is only a one time thing because cats don't handle this type of medicine very well. He has suggested a 1/4 of baby aspirn 3 times a week for two weeks which we are doing, however, it does not seem to help her any.
We are beginning to worry a bit about her health even though the vet said she appears to be in good health.
We have noticed that she is pretty much her normal self, but has been sleeping a bit more lately.
ANy input or suggestions would be a great help!

Thanks!

Thanks! No we do not have a box downstairs yet. She is still able to run up and down the stairs very well. I am sure it hurts her a bit, but sometimes she will run down the stairs like a maniac, LOL! She loves to play ball like a dog. I swear she is part dog

She is the only animal. Yes her food is in the same area as the litterbox, up till now that was not a problem. She does have privacy. There is not much room downstairs for another litterbox. Do you feel having one downstairs anywhere would help or does it need to be in the room where she is pooping. I really did not want a litterbox in the living room, but it's better then having it on my carpet!!!

What would be the next step for the vet? Blood testing?

Yes I did (indicated in my first post ) It was negative. Up until recently, she has NEVER had any elimination accidents since they day we brought her home from the breeder. Thanks

It is the original box, so about 4 yrs old. She will still use that box for urinating all the time, and "pooping" only if she is confined to the upstairs. DO you still think a new box downstairs will help? While I really appreciate the suggestion, I just am trying to understand why for the last 4 yrs one box was fine. Now all of the sudden it may not be.

No....I did not think about that because she will still use the box.

The vet said not to change because cats like pine, and we use feline pine litter. If adding a downstairs box does not work then maybe we would switch litter.

Thanks for all the suggestions, please keep them coming! What litter do you all recommend? I am thinking that we will try another box with a new litter. Maybe also move her food and water as well

No lid, she never seemed to like it.
Also, please recommend a litterbox too

Thanks

I will work on it!

Yes..its the pellet kind

Well we got another litter box (same as the one upstairs) and put it were she has been "pooping". The only change we made was the litter. We are trying Tidy Cat clay litter with crystals.
We put her in the box and scratched the litter with her front paws. So far, she is just hopping out quickly and has not checked it out at all. It has only been set up for about one hour so far, so we will see.......

On other thing that I forgot to mention was that Angel's feces have be kind of dry and hard. Also, smaller than usual. I am wondering if she is a bit constipated. The only thing different we have done recently is be giving her a Lycene gel mixed into her wet food treat once a day. The Lycene was suggested by the vet because Angel has reoccuring conjuctivitis (runny goopy eyes).

She did it!!! While we were out of the house, Angel "peed" and "pooped" in the new box!!
Now, since we have it in the dining room right now (where she was going on the floor), at what point could we move it to it permenant location? The location that we want to keep the new box will be around the corner from the dining room. I am just not sure when I should move it.
Also, she obviously had no problem with the new litter, but the original box upstairs still has the feline pine pellets in it. When confined to the upstairs she was still eliminating in it, so should we leave that one with the Feline Pine? Or switch over to the new? Or even try the Feline Pine in the new box? Maybe the second box did the trick and not necessarily the new litter?

Thanks