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Gastroesophageal Reflux Disease

Gastroesophageal reflux is a normal physiologic phenomenon experienced intermittently by most people, particularly after a meal. Gastroesophageal reflux disease (GERD) occurs when the amount of gastric juice that refluxes into the esophagus exceeds the normal limit, causing symptoms with or without associated esophageal mucosal injury (ie, esophagitis).
Pathophysiology
The physiologic and anatomic factors that prevent the reflux of gastric juice from the stomach into the esophagus include the following:
• The lower esophageal sphincter (LES) must have a normal length and pressure and a normal number of episodes of transient relaxation (relaxation in the absence of swallowing).
• The gastroesophageal junction must be located in the abdomen so that the diaphragmatic crura can assist the action of the LES, thus functioning as an extrinsic sphincter. The presence of a hiatal hernia disrupts this synergistic action and can promote reflux (see image below).
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Barium swallows indicating hiatal hernia.
• Esophageal clearance must be able to neutralize the acid refluxed through the LES. (Mechanical clearance is achieved with esophageal peristalsis. Chemical clearance is achieved with saliva.)
• The stomach must empty properly.
Abnormal gastroesophageal reflux is caused by the abnormalities of one or more of the following protective mechanisms:
• A functional (frequent transient LES relaxation) or mechanical (hypotensive LES) problem of the LES is the most common cause of gastroesophageal reflux disease (GERD).
• Certain foods (eg, coffee, alcohol), medications (eg, calcium channel blockers, nitrates, beta-blockers), or hormones (eg, progesterone) can decrease the pressure of the LES.
• Obesity is a contributing factor in gastroesophageal reflux disease (GERD), probably because of the increased intra-abdominal pressure.
From a therapeutic point of view, informing patients that gastric refluxate is made up not only of acid but also of duodenal contents (eg, bile, pancreatic secretions) is important.

By Shamendri