I see you've written a lot of questions on blurtit! I hope the IVU test goes okay.
The short answer is that you really can't get good quality advice online about this kind of thing, because the answer is so specific to your son and his individual kidney. Plus it's a rare condition that requires trained medics to look at it. If any doubt about the IVU test and suggested treatment, do seek a second opinion from another qualified consultant doctor.
The fact your son is 18 and evidently otherwise healthy, suggests that his kidneys are working pretty well, and may not even be the source of the pain.
Rotated kidneys on their own are often fine and don't necessarily cause problems, especially as you say it's only "mildly" rotated.
There is a higher risk of kidney stones forming in a rotated kidney. Because of the rotation these may have trouble exiting the ureters. I would imagine your son has had an X-ray to look for kidney stones, already, but the small ones can be hard to spot. If a kidney stone is found, there are various treatments (mostly medication that would be taken daily for life, and dietary advice) to get rid of it and prevent them from recurring. Kidney stones would fit with the description of the pain.
If your son were developing kidney disease (irreparable damage) then almost certainly other symptoms would manifest (detected already through the tests you mention). So you can probably rule that one out.
Good luck. I'm sure it's a worry, but it sounds like he's in good hands and "they" are doing everything they can.
The short answer is that you really can't get good quality advice online about this kind of thing, because the answer is so specific to your son and his individual kidney. Plus it's a rare condition that requires trained medics to look at it. If any doubt about the IVU test and suggested treatment, do seek a second opinion from another qualified consultant doctor.
The fact your son is 18 and evidently otherwise healthy, suggests that his kidneys are working pretty well, and may not even be the source of the pain.
Rotated kidneys on their own are often fine and don't necessarily cause problems, especially as you say it's only "mildly" rotated.
There is a higher risk of kidney stones forming in a rotated kidney. Because of the rotation these may have trouble exiting the ureters. I would imagine your son has had an X-ray to look for kidney stones, already, but the small ones can be hard to spot. If a kidney stone is found, there are various treatments (mostly medication that would be taken daily for life, and dietary advice) to get rid of it and prevent them from recurring. Kidney stones would fit with the description of the pain.
If your son were developing kidney disease (irreparable damage) then almost certainly other symptoms would manifest (detected already through the tests you mention). So you can probably rule that one out.
Good luck. I'm sure it's a worry, but it sounds like he's in good hands and "they" are doing everything they can.