A gastric emptying scan is a test that can determine how fast the stomach empties. We run this test by mixing a small amount of radioactivity (known as a 'tracer') with porridge, or an alternative food.  

The tracer is a material that is not absorbed by the stomach. When combined with the food we give you, it will travel through your stomach and intestines. We can then take pictures using a special camera as it passes through.

How to prepare for the scan

  1. We will call you before your appointment to check your current medication, food allergies and medical history. We will let you know if you need to stop taking any medications that may interfere with the test
  2. You will need to stop eating and drinking eight hours before your scan. We usually book the scan early in the morning for you so you can start eating after the test.  

If you think you may be pregnant or if you are breastfeeding, inform us before the injection.

What happens? 

  1. On arrival, we will prepare your food and add the tracer to it
  2. We will ask you to eat the food slowly over a period of up to ten minutes. Gloves and a disposable apron will be provided to you in case the food spills
  3. Once the food is finished, you will lie down on our scanner couch while the special camera takes pictures. It is important you stay as still as possible so we can get clear images during the scan
  4. Over the next two hours, we will take pictures every 15 minutes for one minute each time
  5. You will receive a two-hour break after the scan has finished and you can leave the department. During this time, you cannot eat, drink or smoke
  6. We will ask you to return to the department after two hours to take one last picture. This should only take about one minute.

After the procedure

We will check the quality of your scan during your two-hour break, then you are free to leave the department.

There are no side effects from the injection, so it will not make you feel sleepy or affect your ability to drive.

There is no need to many any changes to your routine, as the radiation dose from this procedure is very small. You can eat and drink normally after the test.

There are currently no related conditions associated with this test.

Getting to the department

Nuclear medicine department

Location Chelsea Wing, Dovehouse Street. Royal Brompton Hospital

Tel: +44 (0) 20 7352 8121.

If you get lost, head to main reception and the team will be happy to help you. 

Please note: The nuclear medicine department does not arrange transport. Your GP can arrange this if there are medical reasons, by calling the Royal Brompton Hospital transport department on 020 7351 8012.

For more information on reaching us, please see general transport information for Royal Brompton Hospital.