That certainly tightens the sphincter . . .
I was scheduled for camera examination of my lungs. The doctor started to explain what was involved, including that access would be via my nose
. At that stage I interrupted him and suggested that he 'just got on with it' without regaling me with the details.
He explained that I would be conscious and it was essential that I was compliant.
I wasn't 'happy', however I was treated to an intravenous dose of a valium-derivative (sort of like those date-rape drugs I believe), so although I related all detail to my wife when I emerged from the 'operation', I soon fell asleep and when I awoke I vehemently denied any knowledge of the procedure.
I've had several more examinations since, and have yet to have any memory of the events.