The X-rays and ultrasound of the kidneys were also normal.
"Then why do I constantly have pain there, and why do I always have foam in my urine," I asked. He didn't know. He guessed that sometimes dietary supplements can cause the foam, but he shrugged his shoulders about the pain. He suggested that drinking more water might help. I already drink about 2.5 quarts per day, but I guess there's room from improvement.
After reviewing the lab report myself, I asked if I should be concerned that my eGFR score (the standard test of kidney function) was only 90. (The "normal range" is given as >60, but people my age are usually in the 120-130 range). In his ethnically ambiguous accent, he said, "forget about eGFR! You've now had the better test." He explained that the 24 hour creatinine clearance test is the gold standard test of kidney function. Apparently, eGFR scores can also drop when a person is consuming a diet high in meat (which I am).
So it seems the kidney-area pain will become another of my unsolved medical mysteries. But at least I have some level of reassurance now that I've pursued that issue as far as I reasonably could and everything appears normal.
Meanwhile, I'm in the middle of a crash. So I guess there's nothing left to do but kick back and listen to The Who, and then maybe catch a movie: