Hi just found this on a website
Signs of Lily Poisoning
The first signs of toxicity are vomiting, depression and loss of appetite. The onset is usually within 2 hours, and may subside by 12 hours. Although an affected cat is likely to remain depressed, the patient may appear to improve, briefly (with or without symptomatic treatment) as the gastrointestinal signs abate. It is likely, however, that acute renal failure will develop within 24 to 72 hour at which time the cat will become critically ill. At this time the patient may drink much more than usual, or become extremely dehydrated. Your vet might feel painful, enlarged kidneys on physical examination at this stage. If untreated, cats die in 3 to 7 days.