Hello There. I can understand your concern. A lot of things can cause pain in abdomen and one of them is calculi i.e., stone anywhere in the urinary tract. since you have got a ultrasound done and it reveals a urinary calculi, the pain is most likely due to that itself. also i was wondering how you don't have symptoms despite have such a big stone. 4.5 cms is a huge stone to have. i think you meant 4.5mm. anyways, its most likely due to the stone itself. consult a general surgeon regarding this for further help. best regards, Dr. Anil kumar jain