Penile injury can certainly be possible. Typically, this diagnosis can be made clincally where a typical sign would be a "popping" sound followed by sharp pain.
Further imaging studies can be done, such as an ultrasound, MRI or a cavernosogram. If there is suspicion that the urethra is involved, a retrograde urethrogram can be considered.
Treatment would depend on the extent of damage. More mild injuries can be treated conservatively with warm compresses, splinting or anti-inflammatories. Surgery should be considered for more severe injuries.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
http://www.straightfromthedoc.com