A gastroenterologist will order a stomach emptying study if there is a chance that the patient is suffering from gastroperesis (delayed stomach emptying). This test times how long it takes for the contents of the stomach to be discharged into the duodenum. The symptoms of slow emptying are primarily nausea, vomiting, abdominal pain, and abdominal fullness after eating. It is common for the patient never to feel hungry.
The test involves eating a specific meal containing a low level radioactive substance. Typically this meal will be something like a scrambled egg sandwich. It will usually be necessary to ensure your stomach is empty prior to the test by fasting overnight.
Once the meal has entered the stomach a series of images are captured using a radioactive imaging device that looks like an X-ray machine. You will need to lie on a motorized bed which is moved into an imaging machine. Around five images are taken over the period of four or so hours. These images will show the distribution of radioactive food in your stomach as it moves around. Eventually the food will move out of the stomach into the duodenum. The technician will measure the amount of food that remains in your stomach as time progresses and from this they will determine if your stomach is retaining food in an unnatural way.