I have had two experiences:
1. I went to see a female nurse practitioner for a mole check about 5 years ago. This involved taking close up photos of any possibly suspect moles and those checked by special software, and sent to a skin cancer specialist to check. I was aked to undress down to my underpants and put on a robe while she left to wash her hands. When she returned she asked me to take off the robe and started to look at every inch of my skin, including the soles of my feet. She made a note of any that needed photographing (about 6) as she went along. When she was behind me, checking my back, she pulled the waistband of my underpants out and quickly looked at my bum (although hardly a thorough check) and when she did my front she didn't look inside my underpants at all. As it happened I did have a small mole at the top of my penis that had appeared a year earlier and I was unsure whether to mention it or not. I decided to tell so she said "OK, we had better take a look then". I pulled my underpants down until my penis popped out. She looked at the mole, photographed it and then asked me to get dressed while downloaded the pictures and ran them through the software. Fortunately none of them were anything to worry about.
I have to say that looking back I think I should have been nude anyway and all areas of skin, even between my buttocks and around my scrotum, should have been checked as a matter of course. After all, as far as I am aware, you can get skin cancer on any skin and, since I am a naturist, most areas of my skin do see the sun at some time or another.
2. Two years ago I went to see my doctor about another issue but while I was there I mentioned a rash I had at the tops of my inside of my legs and on the side of my scrotum, something which used to come and go occasionally but which I had at the time. She asked if she could take a look so I stood up and dropped my jeans and underpants. She was sitting at her desk, and I had been sitting at the side, so I was now standing about three feet from her. She started to lean forward so she could take a proper look but she was just due to go on maternity leave as she was about 9 months pregnant and with the bump at the front couldn't reach. We both laughed at that and she asked me to get on to the examination bed instead. The bed was the opposite side of her room so she pointed to by trousers and underpants around my ankles and said "You had better take those off otherwise you may fall over." I slipped my shoes off, then my trousers and underpants and walked over to the bed. She asked my to lie down and came over to stand next to me. She looked first and then put her hand on my inner thigh and pushed gently while saying "Just open you legs a little for me." She then examined all around, moving my penis and scrotum aside as she did. She also lifted my penis up to look at the area under it. She asked my whether any of the red areas itched and I told her no.
I expected the examination to end there but to my surprise she asked if I had the same marks further around. I said I didn't know so she said "I think I had better take a look. Can you turn over for me?" So I twisted around to lie face down and as I did she added "I'm sorry if this is a bit embarrassing but it is better to make sure." I said "That's OK" not wanting to let on that yes, it was a bit embarrassing but I was actually quite enjoying it. Again she got me to part my legs and then she pulled my cheeks apart and said "There is nothing here" but then I felt her finger touch the back of my scrotum and she added "There is a little bit here." That was the end of the exam so she went over to the sink to wash her hands and asked me to get dressed. I slid off the bed and was relieved to see that I hadn't got an erection even though I felt a few twinges when she had touched me when I was on my stomach. She wrote up my notes and told me she didn't know what the rash was so she was going to refer me to a dermatologist. I told her I had private medical insurance (which meant an appointment in weeks rather than months probably if I was going through the NHS.
A couple of days later I received a letter from the Dermatologists office (a male doctor) giving me a date the following Monday evening at a local private hospital. I can never make Mondays so I rang the office for another appointment but was told he only held his private clinics on a Monday. The secretary said the other Dermatologist held a clinic on a Thursday so I was given an appointment for the next Thursday. I received a confirmation letter the following day and was delighted to see that it was a female doctor.
I went for my appointment and after sitting in the waiting room I was called into an examination room. I sat down and the doctor asked me about the problem and then asked if there was anything else. So I asked if she could also check my moles since I was there and she said she was happy to. She asked me to go behind the screen and get undressed. Since she was going to check my moles, and bearing in mind where my rash was, I took everything off, even my socks, as I would have felt silly being nude but with my socks on. She called out and asked if I was ready. I said I was and she went to the door, opened it and called to the nurse to come in, which I wasn't expecting. They came around the screen and amazingly the doctor seemed quite shocked that I was nude, although the nurse didn't seem to show any surprise. She said "Oh, you could have kept your underwear on." and I replied "I'm sorry, I just assumed that as the rash is in my groin area you would want me completely undressed." She just replied "It doesn't really matter as you would have had to remove them later. Let me check your moles first." She had me stand with my back to her while she looked at each of my moles and then asked me to turn around and looked at those on my front. Actually she was nowhere near as thorough as the mole nurse had been. She said there were no moles to give concern and asked me to sit on the edge of the bed. She put on some rubber gloves and got me to part my legs quite wide while she examined the various rash areas. She also took hold of my penis and checked all around the skin and, then to my surprise, and without saying anything, she rolled back my foreskin. She pulled it back quite hard and checked, not only the skin that effectively formed the inside of my foreskin, but also around my gland too. It was the first time a doctor had ever done that. I was quite surprised that instead of just letting go and letting my foreskin return on its own she carefully rolled it back up my penis. Although I didn't get a full erection I did start to grow a bit but neither the doctor nor the nurse seemed to notice.
She explained she wanted to take a skin sample to have it checked at the lab. The nurse went over to a cupboard and came back with a small plastic specimen container and a scalpel. She unscrewed the lid on the container and the doctor asked her to hold it under one of the red areas at the top of my leg. The doctor then stretched my skin flat with one hand while using the other hand with the scalpel to scrape some skin cells off the rash so that they dropped in the container. I joked that I had better not cough while she had the scalpel there and both of them laughed. I was in seventh heaven I must say having both the nurse and the doctor working between my legs. Unfortunately that was the end so I was left alone to get dressed.
Sorry, that ended up longer than I intended but I was enjoying reliving the experience.