yeah, I just had my iphone 4S dropped into a tub about a month ago.
after drying a few days, it came back all the way. EXCEPT. ... no cellular data or reception for voice. ie; no bars!
somehow it self-healed for a good three weeks was going fine. But last friday...boom no service! wifi worked. bluetooth, touchscreen.
I went to the toggle section of "cellular data, voice roaming" and turned off cell data and then bars would come on for a few seconds .
I attempted to restore while saving my OS in the 5.1.1 or below. no dice!
finally, I had to sacrifice jailbreak and go to iOS 6...and somehow that worked?! it's working now for two days ...
you should open and clean your phone and probably replace battery.
here's something concrete to go by:
What should I do if my iPhone 4S has water damage?