Patients also can develop gastroesophageal reflux disease (GERD) after balloon dilation. Because the LES is the principal barrier that prevents stomach contents from refluxing (backwashing) into the esophagus, LES disruption by balloon dilation can lead to acid reflux. GERD occurs in about 2 percent of people after balloon dilation, but is usually easily controlled with acid-reducing medications. (See "Patient information: Acid reflux (gastroesophageal reflux disease) in adults (Beyond the Basics)".)