What is reflux?

Backward fluid flow.: Reflux generally means that a body fluid is flowing backward, usually in the wrong direction. One example is stomach acid in gastroesophageal reflux disease (gerd), where acid moves back up into the esophagus to cause heartburn instead of exiting to the intestine. In the bladder, vesicoureteral reflux (vur) occurs when urine moves back up toward the kidneys rather than remaining in the bladder.

Reflux: Reflux means leakage of acid into gullet ( oesophagus ). http://patient.info/health/acid-reflux-and-oesophagitis