Brief Answer:
No surgical intervention required

Detailed Answer:
Namasthe
Greetings of the day
Welcome to healthcare-Magic

5 mm calculi is small and can easily pass off the ureter, no surgical intervention is required. It has to be flushed out of calyx by consuming lot of water which increases urine output and flushes it out. Her water intake should be atleast 2.5liter per day. Apart from water intake i would advise some diet modifiction like consuming food low in oxalate, avoid tomatoes and spinach.

Prominence of Pelvicalyceal system on right side could have been to previously present calculi which was causing intermittent blockage and has lead to dilatation. The stone could have passed down the ureter and is no longer seen in the scan.
I would also suggest you to get done certain Biochemical investigation which could be causing the stones and may lead to recurrence. Kindly get Serum Calcium and Phosphate level, and serum Parathyroid level done. Hypercalcemia may lead on to recurrent stone.
Get a repeat scan done after a month to know about resolution of dilatation on right side and passing off of stone on left side.

Consumption of plenty of water and diet modfiication form the mainstay of treatment.
Do consult a Urologist with follow up Scan report.

I hope it helped.
Wishing you a healthy life.
Take Care

Regards
Dr Deepak K K
Consultant Pediatric Urologist

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