Acid reflux was a medical condition in which stomach contents rise into the esophagus.
In 2380, Brad Boimler unsuccessfully tried to claim his acid reflux as justification for being allowed to stay at the Farm on Endicronimas V. A year later, he tried to cite his acid reflux to dissuade the Borg from assimilating him during the Borg Encounter holographic training drill, again to no avail. (LD: "Much Ado About Boimler", "I, Excretus")