Final answer:
Based on the patient's signs and symptoms, a kidney stone is likely located in the ureter.
Step-by-step explanation:
The location of a kidney stone can be determined based on the patient's signs and symptoms. In this case, if the patient is experiencing severe episodic pain in the flank, lower abdomen, and groin, along with nausea and vomiting, the kidney stone is likely located in the ureter. The obstruction caused by the stone can lead to the dilation or stretching of the upper ureter and renal pelvis, resulting in these symptoms. Hematuria, or bloody urine, is also commonly present due to damage to the lining of the urinary tract.