Have Cat Questions? Ask a Cat Vet Online.
Have you seen the vet to rule out a UTI or urinary stones?
Urinary tract infection and urinary crystals are most often the culprit when bathroom habits change suddenly. UTI's can be treated with antibiotics and stones and crystals can be treated with a special diet.
It's a good idea to see the vet at this point to find out what's going on.
Let me know if you still have specific questions about this.