An esophageal motility test shows how well the muscles in your esophagus squeeze and coordinate when you swallow. It measures the strength, timing, and pattern of those contractions, along with how well the valves at the top and bottom of your esophagus open and close. The test is the primary way to diagnose conditions like achalasia, esophageal spasm, and other swallowing disorders, and it’s often required before anti-reflux surgery.
What the Test Measures
The formal name for this test is esophageal manometry, and “manometry” simply means pressure measurement. A thin, flexible catheter with up to 36 tiny pressure sensors, spaced about 1 centimeter apart, is passed through your nose and down your esophagus. As you take sips of water and swallow on command, each sensor records the pressure your esophageal muscles generate. A computer converts all that data into a color-coded pressure map that your doctor reads.
The results reveal three core things:
- Peristaltic vigor: how strong or weak the wave-like contractions are that push food down your esophagus.
- Peristaltic integrity: whether those contractions are continuous and coordinated, or whether there are gaps or breaks in the wave.
- Sphincter function: how well the muscular valves at the top and bottom of your esophagus open when they should (to let food pass) and stay closed when they should (to keep stomach acid out).
The test also measures timing. Specifically, it tracks how much the contraction wave slows down as it approaches the lower valve, which is a critical part of a normal swallow. Problems with that timing can point to specific disorders.
Conditions the Test Can Diagnose
Achalasia
Achalasia is the condition most closely associated with this test because manometry is the only reliable way to confirm it. In achalasia, the lower esophageal sphincter fails to relax properly when you swallow, and the normal wave-like contractions in the esophagus are absent. On the pressure map, your doctor looks for three hallmarks: elevated resting pressure at the lower sphincter, failure of that sphincter to relax during swallows, and a complete loss of coordinated contractions in the esophageal body. The absence of peristalsis is considered essential for the diagnosis.
Esophageal Spasm
In diffuse esophageal spasm, the muscles contract simultaneously rather than in an orderly top-to-bottom wave. The test picks this up when more than one simultaneous contraction appears in a series of ten swallows. These spasms can generate extremely high pressures, sometimes exceeding 200 mmHg (normal contractions are far lower), and the contractions often last longer than 15 seconds and have multiple peaks. Patients frequently experience chest pain during these episodes, which can mimic a heart attack.
A related condition called hypercontractile esophagus (sometimes called jackhammer esophagus) shows up as contractions that are extraordinarily powerful but still sequential. The test distinguishes it from spasm by measuring both the force and the pattern of contractions.
Weak or Absent Peristalsis
On the opposite end of the spectrum, the test can reveal contractions that are too weak to move food effectively. This shows up as low pressure readings or fragmented waves with large gaps. Weak peristalsis is common in conditions like scleroderma and is also relevant for surgical planning, since a patient with very weak contractions may not tolerate certain anti-reflux procedures.
How Doctors Interpret the Results
Results are interpreted using a global standard called the Chicago Classification, now in its fourth version. This system defines specific patterns and pressure thresholds for each motility disorder. One key measurement is the integrated relaxation pressure of the lower esophageal sphincter, which captures how well that valve releases during a swallow. In the general population, the average resting value is roughly 8 to 11 mmHg depending on body position. Values that consistently exceed the upper threshold suggest the sphincter isn’t opening properly.
Another important metric is the distal contractile integral, which rolls the strength, duration, and length of each contraction into a single number. Extremely high values suggest hypercontractile disorders. Very low values indicate weak peristalsis. The current protocol requires swallows in both lying-down and upright positions, plus provocative challenges like rapid swallows or drinking water quickly, to stress-test the esophagus and uncover problems that might not show up with single sips alone.
Why It’s Done Before Anti-Reflux Surgery
If you’re being evaluated for a surgical procedure to treat gastroesophageal reflux, your surgeon will almost always require manometry first. The surgery works by tightening the barrier at the junction of the esophagus and stomach, so your surgeon needs to know that your esophageal muscles can still push food through that tighter opening. If the test reveals severely weak contractions, the surgical approach may need to be modified, or surgery might not be recommended at all. The test also helps rule out achalasia, which can mimic reflux symptoms but requires a completely different treatment.
What to Expect During the Test
The entire procedure takes about an hour. Before the catheter goes in, your nose and throat are numbed with a topical anesthetic. The catheter is then guided through one nostril, down the back of your throat, and into your esophagus. Most people experience a gagging sensation as the tube passes the throat, but it typically fades once the catheter is in position.
Once placed, you’ll be asked to swallow small sips of water at timed intervals while lying down, and then again while sitting upright. You may also be asked to take several rapid swallows in a row or drink a small volume of water quickly. The sensors record everything in real time. Afterward, the catheter is removed, and you may have a mild sore throat for a few hours.
How to Prepare
You’ll need to stop eating and drinking six hours before your appointment. Preparation also involves temporarily stopping certain medications that can affect esophageal muscle function. The list is long and includes some antidepressants, calcium channel blockers, anti-spasm drugs, and certain medications for erectile dysfunction. Your doctor’s office will give you a specific list, but the general rule is to stop these 24 hours beforehand. Blood pressure medications and heart drugs may be on the list, so never stop them without confirming with your prescribing doctor first.
No sedation is needed for the test, which means you can drive yourself home and return to normal activities the same day.