This topic is discussed elsewhere, somewhere... just search for prelim personal statement or some phrase like that.
Basically, i think the consensus is that you can use your same personal statement you are using to apply to anesthesia, because the prelim and transitional year programs all know that you are applying for a different specialty.
Some have suggested to add a line or two at the end of your personal statement for anesthesia saying that you know that prelim medicine (for instance) will give you a well rounded background for your further pursuits in anesthesia... something to that effect.
I've gotten a couple of interviews from prelim med places doing that, so I think it should be ok... i hope! Good luck!
