Woyzeck: You mean I'm only a few years away from a rectal prostate check?
The probability of having prostate diseases and / or erectile dysfunction increases with age. I hope that will not be the case for you, but you will still be able to do preventive exams from the fifties or earlier if you have a family history.
I had never a penis and testicle examination with a general practitioner, only the prostate. By urologists, this examination has always been very fast. I had never an erection exam, theme of this topic. The title is wrong, the doctor will never ask the patient to have an erection, he will cause it himself with an injection into the cavernous body. In some cases, for example a large curvature of the penis, the patient can take pictures at home and show them.