Display Patient Information Leafelts

The Micturating Cystourethrogram (MCUG)

Date issued: May 2013

For review:  May 2015

Ref: B-271/Child health/CD/ The Micturating Cystourethrogram MCUG  

PDF:  The micturating cystourethrogram MCUG [pdf] 61KB


The doctor that you have seen has asked for your child to have a micturating cystourethrogram (MCUG) investigation.


What is a micturating cystourethrogram?

This is a special X-ray of the bladder.  A harmless clear dye is put in the bladder.  This allows the bladder to show up clearly on X-rays.


Why does my child need this test?

This test is done in young children who are having problems with urine infections or because they are born with an abnormality of the kidney tract.  It is carried out to check there is no backflow of urine from the bladder to the kidneys. This back flow is called reflux and can cause infections and kidney damage.  The test can also tell if there is an obstruction at the bottom of the bladder.


How do I prepare my child for the test?

To help prevent infection it is important that your child is on antibiotics for 1 whole day before the test, the day of the test and 1 whole day after the test (3 days total).

If they are already taking trimethoprim increase it as follows:

  • Age 4 weeks to 5 months:

25mg (2.5mls of syrup) twice a day

  • 6 months to 5 years:

50mg (5mls of syrup) twice a day

  • 6 years to 12 years:

100mg (10mls of syrup or 100mg tablet) twice a day

  • Over 12 years:

200mg (20mls syrup or 200mg tablet) twice a day

If they are taking another antibiotic and you have not already been given advice please call Children’s Admissions Unit (number below). If they are not on antibiotics please take this letter to your GP to prescribe you the course described above.

Please bring your child’s favourite toy or comforter.  They can eat and drink normally, so bring milk and snacks with you.

If your child is over 2 years, a preparatory play session at the hospital can be very helpful.  If this is not organised already please call Children’s Admissions Unit 01752 792980 or 245122


What does the test involve?

You will bring your child to the X-ray department.  You will be welcomed, the procedure explained and questions answered.  The Consultant Radiologist (who is a specialist doctor), will gently wash your child’s genital area then put a fine, sterile tube (a catheter) into the child’s bladder.  An anaesthetic jelly on the tube makes it more comfortable. 

Your help in cuddling, playing or reading to your child is much appreciated.  Once in the catheter is usually not felt.  Warm, clear fluid is then put into the bladder.  When full the child will pass urine around the catheter and it will fall out.  This filling and empting is seen on X-ray.  You can then go home.  The test takes 5-30 minutes.  You can stay with your child throughout.

Note: All X-rays involve small doses of radiation.  If you are pregnant you will be asked to stand behind a screen. 


Will my child have any side effects?

Most children experience no side effects.  Occasionally the child may have stinging when passing urine.  Treat this with a dose of calpol, or sitting in a warm bath and encouraging lots of drinks. 

There is a small chance that your child may, temporarily, have blood in their urine or difficulty passing urine.  Rarely a child may get a urine infection and look unwell. If any of these happen go straight to your GP or telephone Children’s Admission Unit on the number below.


How will I get the result?

The results will be discussed at the next meeting with your doctor.


Useful numbers:

If you have any more questions or worries please contact us by any of these numbers:

CAU (Children’s admission Unit Level 12)

Phone: 01752 792980 or 245122

X-ray department Level 6      

Phone: 01752 439285



  1. Rachmiel M et al.  Symptomatic Urinary tract infection following voiding cystourethrography.  Pediatric Nephrol 2005 20: 1449-52
  2. Vates TS et al.  Complications of voiding cystourethrography in the evaluation of infants with pre-natally detected hydronephrosis.  J Urol. 1999;162:1221-1223
  3. NICE Guideline: Urinary Tract infection in children.  August 2007

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