How does the function of the lower esophageal sphincter (LES) relate to gastroesophageal reflux disease (GERD)?

The lower esophageal sphincter (LES) normally remains closed to prevent the reflux of gastric contents into the esophagus. If the LES does not function properly, it can lead to gastroesophageal reflux disease (GERD), where stomach acid flows back into the esophagus, causing symptoms such as heartburn.

The lower esophageal sphincter (LES) is a critical structure that helps maintain the barrier between the stomach and the esophagus. When functioning correctly, the LES prevents gastric contents from refluxing into the esophagus. However, if the LES is weakened or fails to close properly, it can result in gastroesophageal reflux disease (GERD), characterized by the backflow of stomach acid into the esophagus, leading to discomfort and potential damage to the esophageal lining.