I feel that uncircumcised penises are more hot in a medical fantasy, as the doctor can instruct the patient to retract the foreskin to specifically examine the glans. So it adds one more level of exposure and humiliation.
There are various types of medical play possible with an intact penis with foreskin.
You can insert metal implements like a small teaspoon under the foreskin to 'check' for adhesions. It's usually best to put some liquid soap, lotion or lubrication on the spoon metal first. Then you can slowly insert the spoon and move the spoon around over the glans. Or you can use two such things and then pull them apart, so stretching the opening of the foreskin. A nice game to play for checking for or 'treating' phimosis. I used to use wooden popsicle sticks for this until I chanced upon small spoons and some other metal things. Just be sure the edges are not sharp.
The doctor can also insert a finger into the opening and then feel around under the foreskin while it is not retracted. A bit of liquid soap or lotion or massage oil or whatever helps in this instance too.
This kind of play can include frenulum checking with an un-retracted foreskin. But unless doing it to yourself, be gentle with this kind of play. Frenulums are delicate and sensitive things.
And then there is always mock circumcision play or making preparations for a mock/pretend circumcision. This can induce both arousal and a tad of anxiety at the same time.
And there can all sorts of measuring games to be played with a foreskin, using rulers or calipers, to note the length inside or outside, or when stretched up or to measure the opening. Can't do any of that when you're circumcised.