In which condition would you most likely see symptoms of dysphagia due to esophageal sphincter dysfunction?

• A. Achalasia
• B. Barrett's esophagus
• C. Esophageal cancer
• D. Gastroesophageal reflux disease

Answer: (A)

Dysphagia, or difficulty swallowing, is often associated with conditions that affect the motility and function of the esophagus and its sphincters. Achalasia is characterized by the inability of the lower esophageal sphincter (LES) to relax properly, leading to a functional obstruction. In this condition, the normal peristaltic movements of the esophagus are diminished or absent, resulting in food stagnation, regurgitation, and significant difficulty swallowing, especially with solids.

In achalasia, the sphincter dysfunction is primarily due to the degeneration of the neurons in the myenteric plexus, which impairs both the relaxation of the LES and the coordinated contractions of the esophagus. As a consequence, patients experience most notable dysphagia, particularly for solids, but can also develop symptoms related to liquids as the condition progresses.

Other conditions, such as Barrett's esophagus, esophageal cancer, or gastroesophageal reflux disease (GERD), may also be associated with swallowing difficulties, but they do not primarily result from dysfunction of the esophageal sphincters. Barrett’s esophagus is a complication of GERD and does not directly cause dysphagia due to sphincter dysfunction. Esophageal cancer can