The length of time it takes to perform a gastric emptying study depends on how long it takes for the patient's stomach to empty, but Digestive Healthcare of Georgia, P.C. advises patients the test can take at least one hour. The patient lies on his back during the test.
A gastric emptying study evaluates how long it takes for food to transit through the stomach, explains MedicineNet.com. The patient ingests food combined with a radioactive material, and a scanner placed over the patient's stomach monitors the amount of radioactivity in the stomach over a period of time. Delayed gastric emptying causes digestive issues such as nausea, vomiting and abdominal discomfort following meals. Obstruction or abnormal muscle functioning in the stomach also causes this condition.