Take a pair of sunglasses and a bottle of Factor 50 sunscreen to give to the surgeon …
Si
John Doe of San Francisco went for a colonoscopy. As he lay naked on his side on the table, the nurse began the examination. “Don’t worry, at this stage of the procedure it’s quite normal to get an erection,” said the nurse. “I haven’t got an erection,” John Doe said. “No, but I have.” replied the nurse. Moral: Don’t have this procedure done in San Francisco!
A doctor and his patient are seated in the examination room.
The patient, a big guy, says, “Remember when we were kids and I used to beat you up and call you science nerd?”
The doctor says, “You may experience additional ironies tomorrow during your colonoscopy.”
My own low-key one-liner when I arrived for my colonoscopy was to ask if I couldn’t just get the semi-colonoscopy.
I ran in a 5k benefit for colon cancer yesterday. One sign that I saw along the route said:
Innuendos.
I wouldn’t spend too much time planning on a joke. If you don’t think of one beforehand, I’m sure you can pull something out of your ass at the last minute.
I don’t have a colonoscopy joke, but I do have a colostomy joke.
Q. What’s the most difficult thing for a woman with a colostomy?
A. Finding shoes to match her bag.
Hence the user name? 
I thought that was his job??? 
Maybe I’ll try to print out one of this year’s Ig Nobel prize winners and ask if they’ve taken the necessary precautions:
It’s the wrong end, but I had an endoscopy this week (they looked at my esophagus). They put me into “twilight sleep” which seemed to be just sleep.
I’ve been telling people that I feel like a woman who went partying with Bill Clinton (I know, old reference…). I don’t remember what happened, and my jaw hurts.
You don’t have to say anything. Just wink at him.
(rewriting)
Related:
The story goes that Salvador Dali had a very serious eye ailment that threatened his sight. He went to see the leading specialist in Spain and asked his fee. The doctor said, “In your case, an original painting by you on a subject of your choice.” The doctor treated his eye successfully and saved Dali’s vision. Sometime later Dali presented the doctor with an enormous painting of an eye. In the pupil of the eye, Dali had painted a tiny but perfect portrait of the doctor. The doctor looked at the painting in silence for a minute. Finally, he said, “Señor Dali, all I can say is that I’m glad I’m not a proctologist.”
Also related: Dennis Wolfberg on his rigid sigmoidoscopy. Dennis Wolfberg - One Night Stand (3 of 3) - YouTube
The way I heard it (in a high school health class in 1976, hence the archaic sensibilities) is that this decision was made after rejecting “Rears and Queers”, as well as “Nuts and Butts”.
I can’t think of any jokes you can use with your Irish buddy, Colin O’Scopy. Sorry
What’s an innuendo?
It’s Italian for colonoscopy. [The original joke was suppository.]
ETA: I see Mangetout beat me, but not with the full joke.
::snerk:: I did tell 'em to let me know if they found Hoffa - they said in all the procedures they’d done, he had yet to turn up.
I wound up regaling them with a friend’s story: she had the gallon-o-glurge, and didn’t need to finish it all, so the jug was in the fridge. Her husband was trying to wrangle the kids out the door and they weren’t cooperating, and he finally yelled “Last one out has to drink the rest of Mommy’s lemonade!”. They broke the sound barrier.
I may go with the Dali one next time.
You’d think. But OTOH, my dentist had never heard of Frank Zappa’s “Montana” until I told her about it: