I remember going to see a movie as a young child late 's where the opening scene was a young boy getting his temp taken rectally? Does anyone know the name riley steel tube that movie? The boy may have been Ron Howard I do not know if this is movie movie you are referring to but this is what was posted on a voy.
sex movie Bathroom Rectal Temperature
I haven't seen this movie so I can't help you to see if this what you are referring to. I think this movie is called Misunderstood.
Apparently there is a scene that is quite graphic where the boy gets a rectal temp taken. The scene in questions is probably the most graphic I have seen in a mainstream movie, but it still has its limits.
It is not the kid from ET that gets it up the butt, but the other actor Huckleberry Fox. You do see him with his PJs at his knees as his nurse takes it, but the angle is such that your imagination needs to fill in the gaps.
I understand your interest in wanting to see it but when I first saw temperature I was not expecting it so imagine rectal surprise as I watched his nurse pull his PJs down right there on camera.