dull intense lower back pain right side

Hello,
Late last night my fiancee was awoken by a pain in his lower right quadrant. He got up thinking he needed to use the restroom and the pain shifted to the lower right side of his back. The pain became more intense over the next 45 minutes. He stated the pain was dull but intense, and was an 8 on a 1-10 pain scale. He has hx of kidney stones in 2009 on the same side, but states it is not the same pain. Also, he does not have any blood in his urine that is visible to the naked eye. We were just getting ready to leave to go to the ER when the pain suddenly subsided, and dropped to a 1 on pain scale. He said at that point it was still a dull pain that throbbed apporx every 10 seconds, and would occasionally spike to a 3 on the pain scale. The pain was referring towards his penis after the intensity declined. I have suggested he go to have this checked out, but would like to see if anyone has an indication as to what may be causing this? He is 34 yrs old and in great health, is not overweight, and exercises daily. It is not a muscle pain. Any information would be greatly appreciated. thanks!