My 3 year old son complaints sometimes during the day that his penis is hurting. when i ask him to show which part he pretty much shows the whole private area. i cant see any infection or rash. he doesnt like to wear nappy either.

Underlying problem?: Unless your son has had an injury or trauma to his penis/scrotum area, any pain in this region requires investigation by a Dr. Various underlying conditions such as an internal infection, testicular torsion, mass or hydrocele/varicocele etc can be causing this pain. A Dr can examine the area, order tests or images if necessary and decide on a course of treatment.