I have a 12 year old Maine Coon male who has a history of colon issues who has been pooping outside his box off and on for the past 2 years. I have had him checked by the vets, tried a variety of different litters & litter boxes but I acnnot get him to stop this. There is one particular area rug he likes to go on, should I get rid pf the rug? Any ideas? He did have part of his colon removed a few years ago.