Breath Tests for Assessment of Gastric Emptying

Patients are often evaluated for gastric motility disorders, such as gastroparesis by measuring gastric emptying. For nearly 30 years, scintigraphy has been considered the main test for measuring gastric emptying and documenting delayed gastric emptying. There are a variety of ways to measure gastric emptying with scintigraphy with marked variations in the type of meal and duration of imaging. Clinically, it is best to measure the emptying of solids because liquid emptying can often be normal when solid emptying is markedly delayed. Recently, it has become apparent that prolonging the GES for 4 h may improve the diagnostic utility of the test. However, institutions perform the test in different ways with regards to meal content, imaging intervals, and length of test. These differences in performance of gastric emptying scintigraphy at different institutions have made this test less helpful in clinical settings. Scintigraphy is also limited by several drawbacks, including radiation exposure, expensive equipment, and the limited availability of facilities. Thus, there has been great interest in developing alternatives for effective measurement of gastric emptying in a standardized fashion. One such alternative is nonradioactive isotope breath testing.