A number of times when I was a kid, I was at the family doctor for something other than an annual physical, but I ended up having to undress and was examined more than I had expected. But, in those days I pretty much was used to being naked most times when I was at the doctor, for as long as I could remember.
As an adult, I did have a pre-employment physical, which the doctor initially thought would just be asking me questions and him filling out the forms I brought from the employer. But, as the doctor got further down the form he realized they did want more of a complete physical than heād thought. So, he told me I needed to take of my pants and underwear, so he could do a hernia, and rectal exam. So, I quickly went from chatting casually with the med student who was observing, who was friends with relatives of mine, to then wearing only my polo shirt In front of them, and then being bent over the exam table while being probed inside while the med student looked on closely. And, afterwards, I was left standing there for a minute or two while they were writing things, until the med student noticed, and then the doctor told me I could get dressed.
Also, while participating in medical studies, I learned early on that while most studies involve a physical as part of the screening, the extent of that physical may range from just checking blood pressure, heart rate, breathing, height, and weight for some screenings, to a complete physical for others, or could be something in between. Although I havenāt worn underwear regularly for over 30 years, I do try to remember to wear them on days Iām going to a study screening. One early time, I thought I was only going to be interviewed, but the receptionist/assistant did check my vitals. When she asked me to step on the scale, she said first I needed to empty my pockets, or I could just remove my pants. I didnāt want to take everything out of my pockets, so I did take off my pants, but I told her I wasnāt wearing underwear, which she said was fine. (Iād seen role play medfet videos where the patient needed to undress so they could get an accurate weight count, but this was the first time Iād ever actually needed to do that. Since then, Iāve had to undress, partially or completely, with a gown, several times before stepping on the scale in other situations.) Then, she said to just leave those off, while she went to get the doctor, who just came and talked with me some more, while I sat there half-naked. As it turned out, I didnāt qualify for that study, so I never found out how extensive any further physicals might have been. So, these screenings can vary widely, and Iāve learned to expect the unexpected.