All of the above suggestions are good and I have a cat that does this. She has to be on a special diet - Hills Multicare dry and wet - because the condition began with Struvite crystals forming and pressing against her kidney. It was very painful to urinate and she began peeing on the bed because pain was associated with going to the litter box. Surgery took care of the stones against the kidney and prescription Hills keeps the stones from retuning...ka ching ka ching. Her sister cat is the alpha cat so there is also a lot of stress. Ask the vet about FIC,
http://www.animalgeneral.com/ag_news_jan09.html...this does NOT go away! I cover my bed every morning with a plastic drop cloth. It is a lot easier than changing the entire bed! Good luck.