Cat pooping anywhere but litter box

I have a 9 year old cat who has never been the healthiest - he gets ear infections, has had a "stroke," and has recently been diagnosed as asthmatic. He kept getting pneumonia and the doctor prescribed the same medications to treat it 3 times while they figured out why it kept coming back. He has always done very well on these medications, never any noticeable changes. This is what he is taking at the moment to get him through this last bout of pneumonia: clavamox, prednisolone, and theophylline. I know theophylline can make cats a little wired but my guy has always done really well on it.

The problem I am facing now is that he is pooping in random places around the house. His litter box is clean, he is using the same litter and litter box, and eating the same food. The only difference is that we moved at the beginning of the month, but I have moved with him several times and never had a litter box issue.

What do you all think could be the issue? I just spent $600 at the vet last week and have a check up appointment next week so I figured I would check here before spending more money on an additional visit this week. Thanks so much in advance for any help or tips you can provide!

Try retraining him to use the box- confine him to a single room with the box for a week or so. Maybe he needs a "reset". 

Consider getting some Feliway too, could be that he's stressed out from feeling so sick all the time.

I know this isn't what you want to hear but I really would go to the vet to get him checked out first, especially if this is essentially out of the blue- behavior modification will only work if the problem is behavioral, if the problem is medical it won't help and might actually make things worse, so if at all possible you really should rule out a medical issue first.

Cats don't like change, so it is possible that the move, along with the sickness, has just been too stressful for him right now and that is causing this. Cats tend to adapt less well to change as they get older too, so unfortunately his having adapted well to past moves doesn't mean he's going to continue to adapt well.

We have an extremely comprehensive collection of articles about this issue. To make things easiest for you I am liking to a bunch of them here.  I'd also recommend reading these through and trying to get some ideas from them about things that you might be able to do to improve your individual situation.

Good luck.  I know this can be very frustrating

http://www.thecatsite.com/a/how-to-solve-litterbox-problems-in-cats-the-ultimate-guide
http://www.thecatsite.com/a/how-to-choose-the-right-litterbox
http://www.thecatsite.com/a/how-to-choose-the-right-cat-litter
http://www.thecatsite.com/a/how-often-should-i-clean-the-litter-box
http://www.thecatsite.com/a/how-many-litterboxes-should-you-have
http://www.thecatsite.com/a/litter-box-maintenance
http://www.thecatsite.com/a/litter-box-location-secrets

http://www.thecatsite.com/a/combat-cat-urine
http://www.thecatsite.com/a/how-to-remove-cat-urine

http://www.thecatsite.com/a/is-your-cat-stressed-out
http://www.thecatsite.com/a/six-surefire-strategies-to-reduce-stress-in-cats