--that these symptoms followed trauma, compression of either the dorsal nerve of the penis or the major nerve it branches off of, the pudendal nerve, is likely.

It's good they're doing MRI's, but make sure that when they do the one of the pelvis the radiological interpreters are told to specifically look at the pudendal nerve branches and the areas they pass through--soemtimes they pay more attention to the hip bones themselves.

See:

http://www.pudendal.com/

http://www.pudendalhope.org/

http://www.tipna.org/