Which imaging sign is classically associated with achalasia on a contrast study?

• A. Corkscrew esophagus
• B. Hiatal hernia
• C. Bird-beak narrowing at the gastroesophageal junction
• D. Ulceration in the distal esophagus

Answer: (C)

On a contrast (barium) swallow, the classic sign of achalasia is a dilated esophagus with a smooth, abrupt tapering at the gastroesophageal junction, producing a bird-beak appearance. This pattern reflects the underlying problem: failure of the lower esophageal sphincter to relax and absence of normal esophageal peristalsis, so contrast accumulates and the distal esophagus narrows sharply at the LES. The corkscrew pattern belongs to diffuse esophageal spasm, not achalasia. A hiatal hernia is an anatomic finding at the gastroesophageal junction but isn’t the characteristic feature of achalasia. Ulceration in the distal esophagus suggests mucosal injury from reflux or other causes, not the motility disorder seen in achalasia. Thus the bird-beak narrowing at the gastroesophageal junction is the best indicator on a contrast study.