Why is my iPhone 4s screen black?

Hi, I dropped my iPhone 4s in the toilet a few weeks ago, I got it out straight away and I have had it in a box of rice since. As soon as I got it out of the toilet, the screen went fuzzy and went black. Then a few minutes later, the flash light was on and it stayed on for roughly over half an hour. Also, it had water in the light but that is no longer there. The phone vibrates/ makes noise when I put it on charge and vibrates when I turn in on silent. My alarm also goes off in the morning but I am unable to turn the alarm off completely as the screen is just black. Any suggestions will be muchly appriciated if there is anything that could be done to save it.