Unknown body between outside of right kidney and colon.

[Godan_]

I 32 and male, don't have any medical history before. My doc sent me to x-ray for lower back pain checkup. Nothing unusual in my lower back.However, he toldme there might be  stone in your kidney or bladder and he can't tell from x-ray result. So I went again for CT. The CT results shows, there is 12 x11x6 mm pretty ovoid homogenious object between colon and outside of right kidney.They are not sure what it is and it's effect. My doc told me it's nothing to do with cancer, kidney or bladder, and told me to chek it next year if it grows or moves. My lower back pain goes away when I work out and moves around. But I am very worried if this unknown mass is the beginning of something serious