Esophageal diverticula are caused by outpouching of one or more layers of the esophageal wall, classified by their location:

• Zenker diverticulum – proximal to the upper esophageal sphincter
• Traction diverticulum – mid-esophageal
• Epiphrenic diverticulum – proximal to the lower esophageal sphincter

Esophageal diverticula are more common in patients with esophageal motility disorders. Proximal diverticula (ie, Zenker diverticula) can present with oropharyngeal dysphagia, regurgitation, aspiration, halitosis, or a neck mass. Distal diverticula (ie, traction or epiphrenic diverticula) more typically present with dysphagia.

The etiology of esophageal diverticula is unknown, but they are caused by weaknesses in the esophageal wall. Zenker diverticula occur more frequently in elderly patients; distal diverticula occur more frequently in patients with achalasia. Diverticula can also present proximal to esophageal strictures.