What is the hallmark of achalasia on manometry?

• A. Impaired LES relaxation with absent or severely reduced peristalsis
• B. Hyperactive peristalsis with normal LES
• C. Normal LES relaxation and normal peristalsis
• D. LES obstruction with increased peristalsis

Answer: (A)

Achalasia on manometry is defined by failure of the lower esophageal sphincter to relax properly during swallowing, together with little to no organized contractions (peristalsis) in the esophageal body. On high-resolution manometry, this shows an elevated integrated relaxation pressure, indicating incomplete LES relaxation, and absent or severely reduced peristalsis throughout the esophagus. This combination creates functional obstruction at the gastroesophageal junction because the bolus cannot pass easily into the stomach.

In contrast, a pattern of hyperactive peristalsis with a normal LES would point to another motility disorder with excessive contractions, not achalasia. Normal LES relaxation and normal peristalsis would be a normal study. LES obstruction with increased peristalsis would not reflect impaired LES relaxation with absent peristalsis and is not characteristic of achalasia.