Is the "probe" we're talking about here an endo-rectal MRI?

I had a couple of those.  It's a piece of cake.

The instrument was not as big as Schwarzenegger's forearm, but
they did call in Schwarzenegger to insert it.

First, he put a CD of Wagner's "Ride of the Valkyries" in the
sound system and turned it on full blast.  It had the double
effect of pumping him up for the next phase, and masking any
screaming that might otherwise make it into the hallway and
disturb other patients.

Then, while singing along to the music, he put the business end
of the antenna in the proper orifice and gave it a couple of
whacks with a hammer.  He planted his feet carefully and gave it
a few massive twists while muttering "righty tighty left loosey"
and looking occasionally at his right and left hands.

Once it was in, he hooked it up to a 200 PSI air compressor and
blew up the balloon at the end, in order to get the transducer
nice and tight against the prostate.  When my face turned red, he
shut off the air and clamped the hose.

After the traditional "Hasta la vista, baby", he waved goodbye
and turned me over to the nurse, who looked very perturbed and
asked me if my mother knew I was using words like that.

To remove the antenna they called in Hulk Hogan.  The Hulk
apparently didn't know about "lefty loosey" and he turned it the
wrong way for a couple of turns.  But eventually he got it right,
or rather left.  Then he lifted me off the table and stood me up
on my feet, supporting me as he dragged me out to the car.  After
he let me go, I reverted to hands and knees and managed to crawl
into the back seat while my wife drove me home.

The whole thing is over very quickly, no more than five or six
hours and, like I say, it's a piece of cake.  You don't really
have to do anything.  It's all done for you.

   Alan