What Causes Painful Buttocks, Thighs And Back While Having Kidney Stones?

But now the pain on the upper right side of the buttocks , come on the left buttocks too. Some times pain on the thighs and shank( once or twice a day for a few seconds). Feeling numb( like burning sensation) on the thigh, feet, and on the penis, and between penis and anus.( only some times.) lower back pain too. Recently one night I had to get up for urinating with full bladder and had to try very had to urinate( I had more water that night before bed). Another thing one or two times,when I start urinate or start bath room, when I pushed, it felt like the sphincter is closing a few times involuntarily as a try to pass urine or defecation.
I wonder if, it is any nerve problem, it should have been shown in the CT scan, right?
5 months back I was diagnosed with kidney stones of 4mm size in both kidneys. Since then I started drinking a lot of water.