Renal colic pain is most closely associated with stones in which structure?

• A. Renal pelvis
• B. Ureter
• C. Bladder
• D. Urethra

Answer: (B)

Renal colic is driven by obstruction of urine flow and the ureter’s strong peristaltic efforts to move the stone along. The ureter is a narrow, muscular tube, and when a stone lodges or passes through it, the walls distend and contract violently. That distension and spasm produce the characteristic severe, cramping pain that often radiates from the flank toward the groin. The nerve supply of the ureter (T11–L2) helps explain the typical pain pattern. Stones located in the kidney or bladder can cause different, less intense or differently located symptoms, but the classic, dramatic pain of renal colic points to the ureter as the structure involved.