Merely the Patient by Henry Howard Harper

The doctor tapped his desk thoughtfully for a moment, then suddenly his face lit up with some brilliant thought and he wrote out orders for five more examinations. Though I had won my point I didn't like the contented smile with which he handed them to me. I went out felicitating myself on having cleverly side-stepped the stomach test, but a few hours later I discovered the cause of his merriment, for I walked right into another, much worse -- a cystoscopic examination -- where they insert something that feels like a piece of rusty barbed wire into the bladder and up through the ureter into the kidney. Affixed to the inner end of this ingenious apparatus -- which has an opening through the center -- there is a tiny electric light bulb, by means of which they get a view of the interior furnishings. To facilitate this they dilate the parts by pumping in air, soda, transparent acids and suchlike pain-producing inventions.

The process of exploring by alternately probing, twisting, pumping and expanding the inside membraneous walls of the kidney is unpityingly pursued as long as the victim remains conscious; and up to this point is as far as I am able to give an account of the performance. In fact there is no use attempting further to describe it, because no printable language can do it justice.