My cats having problems

Question
I have a white Siamese mix cat. He is healthy and fit, but all of the sudden he is going to the bathroom on the couch. He has a litter box(actually two since we have three cats)and we haven't changed his food or his litter. Nothing has changed we didn't do anything differently, but for the last two days he has been pooping on the couch. I don't know what to do he is fine he isn't stressed or anything. He is scared to go to the bathroom because the other cats. Since he is the biggest cat we have(about 12lbs) he isn't scared of anything. Can you help me I don't know whats causing this or how to stop it. :(

Answer
Christin,

It may be a medical problem instead of a behavioral issue. He may have worms, have intestinal or bowel problems, etc. You may want to have him checked by a vet.

Is he neutered? Even if he is, if he can see stray cats out the window (is there one behind the couch?) he may be reacting to them and it can be stressing him if he can't get to them to defend his territory.

Since I cannot put all the information in this reply, I am including some links to good articles about improper elimination. Please read them. They will have good information that you should find helpful in dealing with the kitten's behavior.
(copy and paste or type the whole links into your address bar)

http://cats.about.com/cs/behavioralissues/a/outsidebox_two.htm

http://www.geocities.com/heartland/pointe/9352/litterboxhelp.html

http://www.apbc.org.uk/article10.htm

I hope this helps.

Tabbi