When my kitty Morgan was having trouble urinating, the vet told me to watch him and make sure he went at least once every 24 hours. If he didn't, then I was go bring him in right away. The kitty may have crystals that are blocking him from being able to urinate properly or perhaps a urinary tract infection that is causing him the problem. Either way, the vet should be able to tell what is wrong and help you help the kitty. Thank you for taking him in and giving him some much needed medical attention. The peeing on the bathmat could be a associated with the urinary problem. Peeing in inappropriate places is often a sign of an infection or other problem. Also, neutering him would be helpful in his overall health and decreasing any desire he may have to mark his territory in your condo.