I got my temperature taken rectally well into my teens and I knew many others who got the same. At the doctor's office the worst thing about it was that the door was rarely closed or just partially closed, so you would be seen by anyone walking in the hallway..
I do remember that as a kid getting my temp taken rectally at home and Dr.s. when very young. I actually got it restarted as an adolescent. When I was 12 or maybe 13 I had begun to use enemas and thermometers "recreationally". When my dad made a dr's aopt. for me once, he had forgotten to tell them something. I was home sick when the office called. I'd always wanted to have it done that way at the Dr's again.
I asked the receptionist on the phone if they took rectal temperatures.
she said: "Umm they can lf ordered. Did you want him to get rectal temps? Is that the way you do it at home?
They must have mistaken me for my dad. I didn't tell them any different. and told her that "he" was used to it that way.
I'd forgotten about it until my appointment a few days later. When taken into the exam room, the office nurse told me "I'm sorry, but it looks like you get rectal temperatures. Is this something you're used to?"
I told her it was and she had me lie on the table. She undid the flimsy strap on my gown and opened it up exposing my bare bottom. left the room to get a rectal thermometer. When she returned, she had my dad in tow. She told him to go ahead and sit down, she had to get a thermometer.
I was mortified. Dad didn't react, merely sat there not saying much, even as the nurse came back in and took my temp. He did ask if we needed to get a rectal thermometer. I told him, 'I dunno" looking embarrassed I guess, because a red tipped Ballo Baby Thermometer soon showed up in the medicine cabinet, well used by me.