Thanks for your query.Based on the facts that you have posted it appears that you have pain in right flank.
This is most likely to be due to what is called as clot colic,Blood clot getting impacted in ureter
and producing dilatation of ureter and kidney
proximal to obstruction.
This is most likely secondary to uric acid stones that you may have in kidney or ureter
Discuss the issue with your Urologist
for reason for treating as Over active Bladder, else take second opinion
of other Urologist.