An esophageal stricture is a narrowing of the esophagus, the tube that connects the mouth to the stomach. People can get an esophageal stricture if they have had a disorder called "gastroesophageal reflux disease" (also called GERD) for a long time. In people with GERD, acid from the stomach backs up into the esophagus. Over time, the acid can scar the esophagus and make it narrower.