American Board of Internal Medicine (ABIM) Certification Practice Exam

What does a barium esophagogram show in cases of achalasia?

1. Widening of the stomach

2. Dilation of the esophagus and narrowing at the gastroesophageal junction

3. Increased motility of the esophagus

4. Changes in the gastric acid secretion

The correct answer is: Dilation of the esophagus and narrowing at the gastroesophageal junction

In cases of achalasia, a barium esophagogram reveals dilation of the esophagus combined with narrowing at the gastroesophageal junction. This occurs because achalasia is characterized by the inability of the lower esophageal sphincter to relax adequately during swallowing, resulting in an accumulation of food and fluid in the esophagus, leading to its dilation. As the condition progresses, the esophagus becomes progressively enlarged above the tight junction, while the area where the esophagus meets the stomach remains tight or narrowed. This characteristic finding is critical for diagnosing achalasia. The other response options do not accurately describe the typical findings associated with achalasia. Widening of the stomach does not specifically occur in this condition; rather, the esophagus is primarily affected. Also, the increased motility of the esophagus, seen in normal peristalsis, does not occur in achalasia, as patients experience reduced or absent peristalsis in the esophagus. Finally, while changes in gastric acid secretion can occur in various gastrointestinal conditions, they are not directly assessed or indicative of achalasia and do not explain the significant radiographic findings seen in a barium esophagogram.