-litter box aversion- dirty litter boxes, changes in types or odors of the litter box
-anxiety
Treatment:
-complete medical work up to rule out pre- existing diseases
-clean soiled areas with enzymatic cleaners
-limit access to soiled areas by confinement
-make the litter box more attractive –offer different types of litter , multiple boxes
-make the soiled area more aversive
-if inappropriate elimination is in a specific location, place the box in those locations until your cat is using the box and move it gradually back to a more appropriate location
Behavior Guides for Cats
Also, you can start a journal of your cat's errant deposits. A simple steno notebook works well. In it, write down the date and time, what you found (urine or feces), where you found it (on a horizontal surface or, in the case of urine, on a vertical one, such as the side of a couch), and the location in the house of the mess (in the bathtub, on a throw rug, next to the litter box). Note taking not only helps you figure out what kind of behavior the problem is and how you should approach it, but also helps you spot even small signs of progress. And perhaps most importantly, having a written record provides you with the information your veterinarian needs to help diagnose any medical problems.
I hope and pray your cat is well.