Gastroesophageal reflux disease (GERD)
![Gastroesophageal reflux disease (GERD)](https://patient.gastro.org/wp-content/uploads/2021/09/Generic_reflux-2.jpg)
Gastroesophageal reflux disease (GERD), or just acid reflux, is when stomach acid frequently flows back into the esophagus. Heartburn is the most common symptom of GERD.
Dyspepsia
![Dyspepsia](https://patient.gastro.org/wp-content/uploads/2021/09/CGH_pt-ed_dyspepsia_2018-1024x883.jpg)
Dyspepsia, or indigestion, may cause upper abdominal pain, burning or heat, and the stomach feeling full during or after eating.
Barrett’s esophagus
![Normal esophagus and esophagus with Barrett's](https://patient.gastro.org/wp-content/uploads/2021/08/CGH-PatientEd-Barretts-2020-min-1024x693.jpg)
Barrett’s esophagus is when the cells lining the esophagus — the tube connecting the mouth to the stomach — change into the cells lining the intestine. The test for Barrett’s is an endoscopy.