Answer:
Whenever sphincter at the base of the esophagus does not function properly this will lead to the reflux of food and stomach acids that is flow of food and stomach to backwards into the esophagus and this eventually leads to the inflamation and irritation of the esophagus lining as a results of the acids reflux, and at the end leads to burning chest or at times sour taste or cough
and anyone suffering from this is said to have a Gastroesophageal reflux disease (GERD)