A voiding cystourethrogram or VCUG is an X-ray test that allows us to see how your child's bladder works. It also takes pictures of the tubes between the kidneys and the bladder, called ureters.

Parents are encouraged to stay with their children during the test, with the exception of pregnant mothers. Kids may bring a comfort object, such as a doll or blanket, and a video to watch during the test. We have limited selection of movies here, as well as a Game Boy that's available on a first-come, first-serve basis.

We find the best way to explain the test to the kids is to describe it step by step:

  • Before the test, children will take off their pants or skirt so they don't get wet during the test. Children can keep their shirts on, or they can put on a gown. When everyone is ready, we'll go into a room with several large cameras connected to a television screen and a long table.
  • Your child will lie down on the table and a doctor or nurse will ask your child to pull his or her feet up close to the body while sticking the knees out to the side "like a frog." We'll wash your child's genital area with a soapy liquid, which may feel cold. Then we'll gently insert a thin, flexible plastic tube, called a catheter, into your child's urethra and into the bladder. We'll tape the catheter to your child's leg to keep it from falling out. Putting the catheter in feels strange and may hurt briefly.
  • A clear liquid, called the contrast material, will flow through the catheter into your child's bladder. This liquid shows up on X-rays, and your child will be able to watch his or her bladder filling on the TV screen. As the bladder fills, your child will feel the need to urinate. We'll ask your child to hold his or her urine for as long as possible.
  • When your child can't hold it any longer, he or she will alert the doctor or nurse, then urinate on the table while the cameras are taking pictures of the bladder. Reassure children that it's okay to urinate on this special table, and they don't need to worry about making a mess.

    While the pictures are being taken, the TV screen will flash on, the lights will dim and your child will hear a low humming sound from the machine above. Some children say it sounds like a train. This may happen a few times. To prevent blurring, it's helpful if your child stays still while the pictures are being taken.
  • Once the pictures are taken, we'll clean your child, then he or she can get dressed and go home. Your child may be a little sore the next few times he or she goes to the bathroom. This is temporary and will go away quickly.

If you have any questions about the test, write them down and we can answer them over the phone or in person the day of your visit.

This test is performed to diagnose conditions such as vesicoureteral reflux (VUR), which causes urine to back up from the bladder into the ureters. See more information about pediatric Urology.