Final answer:
Kidney stones, or renal calculi, can cause severe pain in the flank, lower abdomen, and groin, known as renal colic.
Step-by-step explanation:
Kidney stones, also known as renal calculi, can cause a set of symptoms including severe episodic pain in the flank, lower abdomen, and groin, known as renal colic. This pain is often described as the worst pain ever experienced. Other symptoms include hematuria (blood in the urine) due to damage to the lining of the urinary tract, nausea, and vomiting.