Which symptom is most characteristic of Zenker's diverticulum?

• A. Heartburn after meals.
• B. Regurgitation of undigested food with foul breath.
• C. Epigastric pain after meals.
• D. Weight loss without regurgitation.

Answer: (B)

Zenker's diverticulum classically presents with regurgitation of undigested food accompanied by foul breath. This happens because a false pouch forms just above the upper esophageal sphincter at Killian’s dehiscence, where food can become trapped. The stagnated contents slowly decompose, producing a very bad odor, and can be regurgitated hours after a meal without the need for new swallowing effort. The regurgitated material is usually not actively vomited but simply brought up, which is why it’s described as regurgitation of undigested food with halitosis. This combination—undigested regurgitation plus bad breath—is the most characteristic feature and helps distinguish Zenker’s from conditions like GERD (which causes heartburn), peptic or epigastric pain after meals, or non-regurgitant weight loss.