Which statement about nephrostomy tubes is true?

• A. Drain bile
• B. Drain urine from the kidney when obstruction or hydronephrosis.
• C. Drain bladder
• D. Drain urine from the ureter externally

Answer: (B)

Nephrostomy tubes provide external drainage of urine directly from the kidney when there is an obstruction or hydronephrosis. They are placed through the skin into the renal pelvis to bypass blocked urinary pathways, so urine exits outside the body via a collection bag. This is why the statement describing draining urine from the kidney when obstruction or hydronephrosis is present is true. They do not drain bile (that would be biliary drainage), they do not drain the bladder (that would be a bladder catheter), and they do not drain urine from the ureter externally—the urine is diverted from the kidney itself to an external bag.