Colonoscopy
Don't worry about it. I had a colonoscopy In December last year. Went wearing just t-shirt and shorts, no problems, it all comes off anyway.
They blow you up with air for the procedure so you will fart a whole lot after you come too. The nurses will encourage you to fart as you recover.
I have had three colonoscopy's, all by the same Doctor. At the consultaton, for the third one, I asked the Dr. if we could do the procedure without sedation. He said "Yes", as long as we don't have any complications. I said OK. So, my third procedure was done without sedation. It was like watching TV with the doc for 20 minutes and having a normal conversation. He did one little snip that I didn't even feel. Sometimes you never know unless you ask. And I'm sure each doc. would have his own answer/opinion. If you do the prep correctly. there will be no leakage.