Subtypes & The Chicago Classification

Your manometry report likely includes a Roman numeral: Type I, Type II, or Type III. These categories are part of the Chicago Classification (v4.0), the international system doctors use to define exactly how your esophagus is failing to move food. Knowing your subtype is one of the most important pieces of information you can have, as it predicts how you will respond to different treatments.

The Three Subtypes of Achalasia

While all types involve a failure of the “trap door” (the lower esophageal sphincter) to open, they differ in what the rest of the esophagus is doing.

Type I: The “Classic” Quiet Esophagus

In Type I, the esophagus has completely stopped trying to squeeze. It is “aperistaltic,” meaning there is 100% failed movement ^[1]. This is often considered a later stage of the disease, where the esophageal muscles have become exhausted and the tube may have become dilated (stretched out) ^[2].

Type II: The Pressurized Esophagus

Type II is the most common form. While the esophagus doesn’t coordinate a normal swallow, it builds up pressure throughout the entire tube—a phenomenon called panesophageal pressurization ^[3]. This pressure actually helps “push” food through the tight sphincter once it is treated. For this reason, Type II consistently has the best prognosis and the highest success rates across all treatment types ^[4][5].

Type III: The Spastic Esophagus

Type III is the rarest and most complex. In addition to the “stuck” trap door, the esophagus has abnormal, powerful, and often painful spastic contractions ^[1]. Because these spasms can occur higher up in the esophagus, Type III requires a different approach to treatment to ensure the spastic areas are properly addressed ^[6].

How Your Type Drives Your Treatment

Your subtype acts as a guide for your medical team when choosing between the primary treatment options.

• Type I and II: These types respond very well to Laparoscopic Heller Myotomy (surgery), POEM (endoscopic procedure), and sometimes Pneumatic Dilation (stretching the sphincter with a balloon) ^[4].
• Type III: This type strongly favors POEM. During a POEM procedure, the doctor can perform a “longer myotomy”—meaning they can cut the muscle further up the esophagus to neutralize the spastic contractions that are causing pain and blockage ^[6][7].

When the “Gold Standard” Isn’t Enough: FLIP

Sometimes, a standard manometry test (the “gold standard”) doesn’t provide a clear answer. In these cases, your doctor may use FLIP (Functional Luminal Imaging Probe) panometry ^[8].

During an endoscopy, a small balloon is inflated in your esophagus to measure its distensibility index (DI)—essentially how much the “trap door” is willing to stretch ^[9]. If your DI is low, it confirms that the opening is too tight, providing the evidence needed to move forward with treatment even if your manometry was inconclusive ^[8][10].