kitty..pooping/eating problem

hellu everyone,
Well I got this sweet persian kitty.. I called him Biso.. he has been living with me for about 1.5 months..(hes like 3 months old)
Everything about him is amazing..he never urinated or defecated outside the litterbox even on his first day in my house!!.. but lately he seemed to discover the pattern and started defecating outside the box..!! well.. here is the deal.. My mom is a neat/clean freak.. and ever since he got here.. she suggested that we wipe his behind with soft wet tissue paper everytime he defecated.(is that right.. if not wat can i do .!?) and so we started doing that.. and sometimes when he had diahheria we had to wash his behind and so he started hating the sink and a while ago he quite defecating in the box and is doing it on the carpet (still urinates inside the litterbox tho- maybe coz we dont wipe him when he does it there!)..i have tried puttin his food where he poops but he wouldnt eat it..i tried citrus smell.. no use... maybe it wasnt strong enough!.. any help is greatly appreciated..
One more thing.. this guy is quite spoiled lol.. if I feed him some cat food for a day or so.. he stops eating it.. if I feed him any kind of food for a day or two he hates it and stops eating.. the vet said I shouldnt change his food type at alll coz it would cause some ingestion problems..anything I can do !?
Thnx in advance

I would suspect your cat is ill and that is why he is pooping outside the box. Health issues should be ruled out first.

Once he has been to the vet, and if it is determined he is healthy- then you need to look at several things- first, he should have two litter pans not one. He is growing, so the standard litter pan may not be big enough for him, so you need to go to a larger container. How often is the box scooped? cleaned? is fresh litter put in, or just dumped on top of the old stuff? Cats are tidy and fastidious creatures, if a place smells, the cat will move off to another place that has no smell and do their business there.

Also www.odordestroyer.com or www.urine-off.com carries products you need to clean the places where he missed- but a vet visit should be your first stop

thanx for the advice.. but I took him to the vet a couple of days ago and he is perfectly fine. Also, the maid scoops his litterbox everyday..and i get him sand every once in a while.. but i tried something today: I took out the carpet where he used to poop and wiped the place with some terpanin liquid.. he seems to hate it.. but anyway he did it in the box today..altho i suspect he will find him another place to poop pretty soon!!
anyway..what about food tho? should I give him variations or stick to one kind only...even if he stops eating it after a while coz he hates sticking to one type of food?
thnx