Can non-obstructing calculus in inter-polar region of kidney, size was 0.3cm last year now 0.4cm. the reason i ask is that i have had mild flank pain for 3-4 weeks ?

Stone pain: This can be painful although the stone is not obstructing. See your urologist for recommendations of how this should be handled. if it is entering then receding from the duct can cause some pain and intermittently bleeding. see the doc for better advice.

Sure: check with your doc how to get rid of this stone. Usually a lot of water will flush it out. But better to be sure and have it taken care of. Good luck.