When you undergo a medical exam you will get tested for: Syphilis and HIV, and X-ray for Tuberculosis and a Urine exam.
The last one, if you have kidney stones might come abnormal and this might prompt the physician to request additional exams. For instance, if they find hematuria (blood in your urine) or calcium oxalate crystals (most common type of kidney stones) the physician will most certainly have to investigate why that is.
Responding to what
ENGR1 said, yes there is no ultrasound but it doesn't matter. US is not a good method for kidney stones detection anyways. Its is certainly a case by case basis. If you decide to hide your kidney stones history from the physician that is up to you.
I highly doubt anyone would ever get their visa refused simply for having kidney stones, since many people develop them at some point during their lives (including myself) but in most cases with no permanent consequences.