Don't use disinfectant though or anything that contains ammonia as this will encourage the cat to wee again in the same spot. Get your cat checked for a urinary tract infection maybe? Sometimes the case when a previously clean cat starts weeing in the house.
oh i dont think she has an infection. she is currently recuperating from an operation to have her tail amputated and i'm keeping her in my room, i think she thought she was totally in the litter tray (she's not used to having to go in a tray) but obviously her rear end was hanging off the edge as it has gone on the floor. i've put plastic sheet on the floor under the tray now to prevent it happening again.
Poor kitty. Hope she recovers soon. My old cat ALWAYS did that, she almost never managed to get her business in the tray but would laboriously scoop the litter out of the corner, stand in the hole, poo over the side and then stand and look at it with a most confused look on her face. She would then spend several minutes scraping the side of the tray with her paw and occasionally look at the poo still sitting there, scrape a bit more and finally give up