Renal colic — the pain of a ureteric stone — is among the most severe pains in medicine, typically described as coming in waves, radiating from the flank to the groin. Most stones smaller than 6mm pass spontaneously within four weeks; larger stones or those causing complete obstruction often require urological intervention. The combination of ureteric obstruction and urinary tract infection constitutes an infected obstructed system — a urological emergency requiring urgent drainage by ureteric stent or nephrostomy tube, as sepsis can develop rapidly. Any stone patient with fever, rigors, or systemic illness should be seen immediately.
