Esophageal Physiology: Role of Lower Esophageal Sphincter in Gastroesophageal Reflux

The esophagus plays a vital role in transporting food from the mouth to the stomach. At the junction of the esophagus and stomach lies the lower esophageal sphincter (LES), a critical component in preventing gastroesophageal reflux disease (GERD).

Function of the Lower Esophageal Sphincter

The LES is a muscular ring that remains contracted to prevent stomach contents from flowing back into the esophagus. When swallowing occurs, the LES temporarily relaxes to allow food to enter the stomach.

Pathophysiology of GERD

• Weak LES function allows acid reflux.
• Increased intra-abdominal pressure worsens reflux.
• Hiatal hernia can impair LES function.

Management and Treatment

GERD can be managed through lifestyle modifications, medications, and surgical interventions. Proton pump inhibitors (PPIs) and H2 receptor antagonists help reduce acid production, while fundoplication surgery reinforces LES function.