Rereflux with hiatus hernia

Depiction of a radionuclide acid clearance study in a subject with a hiatus hernia. Fifteen seconds after the injection of a 15 mL bolus of 0.1 N HCl labeled with 200 microcuries of 99mTc-sulfur colloid, subjects swallowed every 30 seconds. The vertical axis represents the region from the sternal notch to the stomach. The horizontal axis is the time scale. The radioactivity is represented by the black area and no radioactivity is represented by the absence of black color. Soon after injection, the radioactivity appears in the stomach. However, there is reflux of isotope into the esophagus followed by clearance of the isotope during each of the first three swallows.