I can’t remember if it was the exact same procedure, but I’ve had something very similar when I had a bladder biopsy done, but I’m going to beat you on making someone else uncomfortable :D

For anyone who doesn’t know, these procedures start with an anaesthetic gel being squirted into your penis through a syringe to numb everything, then the camera and tools get inserted. It’s been a while, but from what I remember, some air gets pushed in along with everything else. The nurse warned me that the air coming out can be uncomfortable. I also had to have a pretty full bladder for the procedure.

Afterwards, I needed to pee straight away, so used the toilet next to the waiting room. When I went, it burned a bit from the gel wearing off and everything just generally being tender. Suddenly though, I had this feeling of intense pressure, and a fireball forced its way out followed by some boiling pee. I used my free hand to steady myself, and my knees almost buckled. I let out an involuntary ‘Jesus Christ!’. I finished and cleaned up, and the nurse met me outside the door.

She had a huge grin on her face, and said ‘I told you it would sting’, then nodded towards the waiting room, where about half a dozen terrified looking men had apparently heard me :D

probably depends on the size of the kidney stone. i had a rather small one, and it wasn’t nearly as bad as having an appendicitis getting so bad it burst. sharp pain from knees to jaw, trembling in very high fever. had to wait for almost 20 hours for the surgery in that condition. and the meds did absolutely nothing at that point