Renal colic is a common (1300 visits per year at our institution) and painful condition caused by stones in the kidney and ureter, and can be mimicked by life threatening conditions such as a ruptured abdominal aortic aneurysm (AAA). This can create clinical uncertainty. Emergency department targeted ultrasound (EDTU) is performed by an emergency physician at the patient's bedside, and has been shown to be accurate, safe, and efficient. We have shown that EDTU can accurately identify hydronephrosis, which is a predictor of complications of kidney stones. A normal formal ultrasound (US) predicts an uncomplicated clinical course. We will assess the accuracy of EDTU for the diagnosis of hydronephrosis, and when normal, whether patients can be safely discharged.

Inclusion Criteria:

• Age 16 - 65 years
• Symptoms suggestive of renal colic
• EDTU performed within one hour (before or after) of formal imaging
• Imaging study arranged during this ED visit (includes next morning)

Exclusion Criteria:

• Hemodynamic instability (Pulse > 120 or SBP < 90 or requiring vasopressors)
• Fever (>38 degrees C)
• Leukocytes and nitrites on dipstick urinalysis (evidence of urinary tract infection)
• Pregnancy
• Inmate
• Renal transplant or single functioning kidney

ED patients with suspected renal colic being imaged while in the ED