Stolen ipod, jailbroken help?

so a few weeks ago my ipod touch 3G was stolen and i was lucky enough to get it back. but when it was returned to me of course everything i had on there was gone and it was jailbroken. is there any way to completely unjailbreak it? remove all traces of it ever being jailbroken? also is it possible to get all my info back on it? i have my itunes account with everything on it still so could i just plug the ipod in and have everything synced back onto it without a problem?