male cat pooping everywhere except the litter box

Question
My cat is a Himalayan 7 year old,nurtured indoor cat. Due to the extent of this problem our vet has recommended possibly an ulcerated colon due to food allergy. We then changed food to only human grade pet food for allergen problems and treated him with prescription. For a while it appeared to solve the problem except for 2 to 3 days a week we would still have the problem. Now after 6 months he still defecates everywhere and from time to time he will urinate on our bed. Our cats ( we have him & his brother which does not have this problem) have always had the automatic litter box since day 1 & the box stays cleaned on a daily basis. We are at our wits ends on this and I am sometimes concerned as to the possibility of something more wrong with him. Example this a.m.: he started meowing to me and 'digging' on our carpet. I immediately picked him up & placed him in the litter box where he promptly defecated then he jumped out. If I had not been there to notice his actions - he would have defecated on our carpet. I have noticed since all this has started that his feces is extremely large in diameter (larger than our terrier dogs), more feces than his normal amount and it has a very nasty odor ... worse than the usual smell of felines feces. Not that I am an expert on this .. except due to him NOT covering up his feces ... if I happen by the box & find it before the box cleans it up I will cover it up at least to keep the smell down. If you can assist us we would be forever grateful. We are at our wits end.

Answer
Sha,

It seems to me that this cat has a physical problem and you are doing the right thing by going to the vet.  However, the physical problem has become a behavioral problem for some reason.  

It is possible that the automatic litter box made some kind of noise when he was doing his business and frightened him.  There may be something else that happened that made him leary of that litter box.  So, I would try a non-automatic, old timey litter box and see if it makes any difference.  I would put the litter box away from the automatic litter box.  Also, did you change your bramd or type of litter when all this started?  A change in cat litter upsets some cats.

It does bother me that the odor is so bad.  I would check with your vet to see if he can ascertain the source of the odor.  At least the cat does not have diarrhea.  It may be something as simple as his anal glands needing to be expressed.

As to the inappropriate urination, you might have your vet check his urinary tract as problems herein can cause inappropriate urination (bladder infections, kidney infections, cystitis, stones, etc.).  If it is not a physical issue, one thing you might do where he wants to urinate inappropriately is to put up a Feliway diffuser (available from most pet supermarkets) and see if that helps the urination problem.  
You might also want to read the following article:

http://www.netcat.org/housesoiling.html


Finally, for cleanup, you should use an enzyme based cleaner specifically for pet stains and pet odors (available at pet supermarkets or farm stores).

Best regards... Norm.