Pain radiating downward to the groin may indicate that a stone has passed to which segment?

Pain that radiates down to the groin is typically associated with the passage of a urinary stone through the lower third of the ureter. The ureter is the tube that carries urine from the kidneys to the bladder, and the lower third of the ureter is particularly relevant because it is in this area that stones can exert pressure on surrounding nerves, leading to referred pain felt in the groin area.

As the stone moves down the ureter and approaches the bladder, the patient is likely to experience sharp and intense pain that follows this path. This symptomatology is consistent with the classic presentation of renal colic, where the pain starts in the flank and then radiates anteriorly toward the groin, suggesting that the stone is in transit through the lower ureter.

Additionally, pain originating from the upper ureter, bladder, or renal pelvis typically does not radiate to the groin in the same characteristic manner seen with stones lodged in the lower ureter. Therefore, recognizing the significance of pain location and its relation to the anatomy of the urinary tract is essential for an accurate clinical assessment.