not using his litter

Question
Hi I have a 4 year old cat who is just the sweetest thing in the world. last fall he started to poop on my bed
at first i didn't know what to do i figured he was sick. so i took him to the vet did a whole range of test and he is fine,but he keped doing it, but only when i wasn't home. so i started closing my bed room door all the time. that worked for a while . then he started doing it on the living room carpet. i cleaned it and put a spray the vet told would get the smell out. but that didn't work. i tried to put some dry food on the carpet where he would go that worked but only for a while. Now i look him up in the bathroom when i leave . he started sing his box again but only for a while now he is pooping on the bathroom floor or in the tube. i tried to change the litter i change his box. i feel bad for looking him up but i don't know what else to do. can you help me please

Answer
Hi Karen,

Here's a great link and article that should help you. It is going to take a little bit of detective work to figure out what is causing him to do this. But you will be able to find why he is doing this and correct the problem. Good luck.
http://cats.about.com/cs/behavioralissues/a/outsidebox_two.htm

Ciao, Karen