I am also facing the same problem.I have burning lik pain in the head of penis, and some in the testicle. I have had numerous test, kidney stones,UTF, all negative. When I urinate I have a burning felling. However I was told that my L1 and L2 disc are bad and this is probablr the cause. I find this hard to believe.
I got the infection on my pennis and at the time of urinating burning sensation.I got infection in my urine i.e acidic
Also I am getting burning sensation in my foots and pams for some times.