Hi, I Recently Had X-ray Kub Test And The Result

Hi,
I recently had X-ray Kub test and the result was :`` Radio-opaque shadow is seen along the line of right mid ureter may calculus/faecolith.

And the Recommendation was: USG of KUB please.
Please guide me to properly interpret this result and further advice as I really worry due to the persistent constipation and rectal pain I am going through.