A gastric emptying study is a medical test that tracks how quickly food moves from your stomach into your small intestine. It helps healthcare providers understand if your stomach is functioning as expected or if there are issues with its emptying rate. This test can help identify the root cause of persistent digestive problems like nausea, vomiting, or bloating, guiding diagnosis and treatment.
Understanding Gastric Emptying Studies
A gastric emptying study, commonly known as gastric emptying scintigraphy (GES), is a nuclear medicine test that measures how quickly contents leave the stomach. This process, called gastric motility, involves the stomach’s muscles contracting to move food into the small intestine, which is essential for digestion.
The study involves consuming a small meal with a harmless radioactive tracer, such as Technetium-99m Sulfur Colloid. A gamma camera tracks the meal’s movement, taking images at specific time intervals. This allows medical professionals to calculate how much of the meal remains in the stomach over time, providing a precise measurement of its emptying rate. This non-invasive method offers valuable insights into stomach function.
Reasons for the Study
Medical professionals recommend a gastric emptying study for symptoms suggesting impaired food movement through the stomach. These include feeling full quickly, persistent nausea, frequent vomiting, unexplained weight loss, bloating, or upper abdominal discomfort.
The study diagnoses gastroparesis, a condition where the stomach empties too slowly due to impaired muscle function. Diabetes is a common cause of gastroparesis, as high blood sugar can damage nerves, including those controlling the stomach. The test also identifies rapid gastric emptying, known as dumping syndrome, which often occurs after stomach surgery. It can also help evaluate chronic nausea and vomiting, reflux disease, or other gastrointestinal disorders where abnormal gastric emptying is a contributing factor.
The Procedure
Preparing for a gastric emptying study involves specific instructions to ensure accurate results. Patients fast for several hours before the test, often overnight. Certain medications that affect stomach motility may need to be temporarily stopped or adjusted. Patients with diabetes receive special guidance on managing their blood sugar levels and insulin doses on the day of the test.
During the study, patients consume a standardized meal, usually scrambled egg whites with the radioactive tracer mixed in, along with toast, jam, and water. The entire meal must be eaten within 10 minutes. After finishing the meal, the patient lies or stands in front of a gamma camera, which takes initial images of the stomach. Subsequent images are captured at one, two, and four hours after eating.
The test takes between two and four hours. Patients can move between imaging sessions but must return for scheduled scans. The procedure is non-invasive and causes no pain, though some individuals might experience mild discomfort from hunger or lying still.
Interpreting Results
Medical professionals analyze the images to determine the percentage of the radioactive meal that has emptied from the stomach at each time point. This data is compared to established normal ranges. A normal result shows less than 60% of the meal remaining after two hours and less than 10% after four hours.
If a higher percentage of the meal remains in the stomach at later time points, it indicates delayed gastric emptying, consistent with gastroparesis. Conversely, if the stomach empties faster than the normal rate, such as more than 70% emptying within one hour, it suggests rapid gastric emptying or dumping syndrome. These findings help healthcare providers confirm a diagnosis, assess the severity of a motility disorder, and determine the most suitable course of action for managing the patient’s digestive symptoms.