Before you order a foley catheter which is one of the more painful procedures in emergency medicine, first check to be sure that the bladder is distended. This is quick and can really help guide therapy – insert foley, replace foley, look for problems elsewhere if the bladder is empty. 2 minute video here.
The primary question for renal POCUS is that of hydronephrosis. It’s presence strongly points towards renal colic as the diagnosis in the appropriate patient. 2 minute video here.