What Is an Esophageal Manometry Test?

Esophageal manometry, also known as an esophageal motility study, is a test used to diagnose problems involving the movement and function of your esophagus (the tube that runs from your throat to your stomach). The procedure involves the insertion of a pressure-sensitive tube into your nose that is then fed into your throat, esophagus, and, stomach. Esophageal manometry is used when you have a chronic reflux or swallowing problems that cannot be explained.

Purpose of Test

Esophageal manometry can help determine whether your problem is associated with the esophagus itself and, if so, in which part and to what degree. Specifically, it is used to detect esophageal motor dysfunction. This refers to problems involving peristalsis (the involuntary, rhythmic contraction that helps propel food to the stomach) or the valves, called sphincters, which open and close whenever you eat or drink.

The esophagus contains two such sphincters:

• Lower esophageal sphincter (LES), located at the entrance of the stomach, which prevents food and acid from backing up (refluxing) into the esophagus
• Upper esophageal sphincter (UES), positioned beneath the throat (pharynx), which prevents air from getting into the stomach or its contents from getting into the lungs

Indications

Esophageal manometry may be recommended if you have dysphagia (difficulty swallowing), odynophagia (painful swallowing), or symptoms of reflux that resist treatment (including heartburn and chest pain).

However, esophageal manometry is usually not the first test used to diagnose these conditions. Rather, it would be performed after X-rays and other tests have ruled out more likely causes, including esophageal obstruction, esophageal stricture, hiatal hernia, or heart disease.

Esophageal manometry may be used to help diagnose: 

• Achalasia, the dysfunction of the LES in which food is unable to pass into the stomach
• Eosinophilic esophagitis, an allergic cause of dysphagia
• Jackhammer esophagus (hypercontractile peristalsis), characterized by esophageal spasms in an abnormal sequence
• Nutcracker esophagus (hypertensive peristalsis), characterized by rapid esophageal contractions in a normal sequence
• Scleroderma, a rare disorder that causes the chronic tightening of tissues, including the throat

The test is not used to diagnose​ gastroesophageal reflux disease (GERD) but rather to characterize the nature of the disease. It may be recommended if you fail to respond to GERD therapy or if anti-reflux surgery is being considered.

Limitations

While manometry is useful in identifying motility problems, it does have its limitations. Given that spasms and swallowing problems are often transient, there is no guarantee they will occur during the test. This may lead to inconclusive or ambiguous results.

Because of this, many people with esophageal dysfunction will have normal motility parameters after testing. By contrast, abnormal findings may sometimes have no relation to the symptoms you're experiencing. It is for this reason that expert consultation is needed if the findings are anything less than conclusive.

​Alternative Tests

While a conventional esophageal manometry is the best method for assessing motility dysfunction, there are other tests that may be more appropriate for other conditions. Among them:

• Barium swallow studies may be used to evaluate the function of the esophageal sphincter by recording the movement of the liquid with a live X-ray video camera.
• High-resolution manometry, which is more costly, works similarly to a conventional manometry but uses more sensors to create a three-dimensional map to pinpoint asymmetrical sphincter problems.

Risks and Complications

While the very thought of esophageal manometry may seem off-putting, it is a relatively safe procedure and usually nowhere near as uncomfortable as you might think.

Occasionally, during insertion, the tube may enter the larynx (voice box) and cause choking.

Complications are rare but may include:

• Arrhythmia (irregular heartbeats)
• Aspiration (the inhalation of stomach contents)
• Esophageal perforation
• Epistaxis

Many of these can be avoided by following the pre-test instructions provided by your healthcare provider. Testing is contraindicated if there is any obstruction of the pharynx or upper esophagus, including benign or malignant tumors.

Before the Test

An esophageal manometry does require some preparation on your part. While intubation (having a tube inserted into your throat) may seem awkward, every effort will be made to ensure that you are as comfortable and relaxed as possible.

Timing

The test itself takes around 15 to 30 minutes to perform. Barring delays, you should be in and out of the office within 60 to 90 minutes. Esophageal manometry is often performed in the morning to ensure your stomach is empty. It is best to arrive a half hour in advance to sign in and settle.

Location

Esophageal manometry is an in-office produce typically performed by a gastroenterologist. The test is performed with a manometry unit consisting of a computerized module, a digital display screen, and a 2.75- to 4.2-millimeter flexible nasal catheter. The catheter itself is equipped with eight sensors able to detect subtle changes in esophageal pressure.

What to Wear

It is best to wear a loose-fitting outfit. You won't be asked to undress but will be provided a hospital gown to protect your clothes from water and gels used for the test.

Food and Drink

To avoid aspiration, you will be asked to stop eating or drinking anything, including water, four to six hours before the test. If this instruction is not followed, the healthcare provider may have to cancel and reschedule your appointment.

Medications

There are a number of medications that can affect the motility of your esophagus. Some need to be stopped to ensure they do not interfere with the testing. 

To this end, always advise your healthcare provider about any drugs you are taking, whether they be pharmaceutical, over-the-counter, traditional, homeopathic, or recreational. The healthcare provider will be able to tell you which, if any, need to be stopped and for how long.

Among some of the classes of drugs that may be problematic:

• Anticholinergics, such as Spiriva (tiotropium), Atrovent (ipratropium bromide), and Ditropan (oxybutynin)
• Calcium channel blockers, such as Norvasc (amlodipine) and Cardizem (diltiazem)
• Nitrates, such as nitroglycerin, Viagra (sildenafil), and Cialis (tadalafil)
• Promotility agents, such as Reglan (metoclopramide) and Zelnorm (tegaserod)
• Sedatives, such as Versed (midazolam) and Ativan (lorazepam)

Cost and Health Insurance

The cost of a conventional esophageal manometry test can run from around $500 to $1,000, depending on the provider and location. These costs may be covered in part or in full by your health insurance.

The test requires insurance pre-authorization, which your gastroenterologist can submit on your behalf. If approved, it is important to know what your co-pay and out-of-pocket expenses will be. If you cannot afford these costs, insured or not, speak to the gastroenterology administrator about a monthly repayment plan.

If you are denied coverage, ask your insurer for a written reason for the denial. You can then take the letter to your state insurance consumer protection office and ask for help. Your gastroenterologist should also intervene and provide additional motivation as needed.

Other Considerations

Sedatives are not used for an esophageal manometry test. As a result, you can usually drive yourself to and from the healthcare provider's office without concern. 

During the Test

On the day of your test, after signing in and confirming your insurance information, you may be asked to sign a liability form stating that you understand the purpose and risks of the test. You would then be taken to an examination room.  

Pre-Test

The esophageal manometry test is usually performed by a specially trained gastrointestinal (GI) motility nurse. Either a doctor or a GI registered nurse (certified by the Society of Gastroenterology Nurses and Associates or other certifying bodies) is qualified to oversee the procedure. A nursing assistant may provide support.

Upon entering, you will be provided a hospital gown and asked to sit on an examination table. You will need to remove your glasses and anything in your mouth that could be dislodged, such as a tongue piercing.

Sedatives are not used because they can over-relax the esophagus and interfere with the test results. A topical numbing agent may be used to help ease discomfort.

You will likely be given the choice of which nostril to use for the test. (The nasal route is preferred as it is less likely to cause gagging than the throat.)

A GI motility nurse is highly trained in this procedure. Try to relax by slowing your breathing, relaxing your shoulders, and unclenching your fists. If you feel any discomfort, let the nurse know without panicking.

Throughout the Test

An esophageal manometry test can vary by the type of equipment used but more or less follows the same basic steps:

1. Before inserting the catheter, the tip is lubricated with the topical anesthetic. Your nostril may also be lubricated.
2. As the catheter is inserted, it will reach a point of resistance as it makes an acute angle into the throat. You may be asked to tilt your head down to help ease the catheter in.
3. To move the catheter past your UES, you will be asked to sip water through a straw. Doing so opens the sphincter, allowing the catheter to enter with minimal resistance. 
4. Once the catheter is past the UES, it is quickly fed into the esophagus and stomach. The catheter is then taped in place and you are asked to lie on your side.
5. The healthcare provider then starts to calibrate the catheter sensors. At this point, you need to refrain from swallowing to ensure the calibration is correctly set.
6. Testing begins when the two last sensors are correctly positioned in the stomach. The sensor is set at zero to serve as the baseline for comparison.
7. As the catheter is withdrawn to the LES, you are asked to take several sips of water. Doing so allows the healthcare provider to measure changes in the sphincter pressure from a closed state (before swallowing) to an open state (after swallowing).
8. You will take additional sips of water to measure changes in esophageal pressure as you swallow. If peristalsis is normal, your healthcare provider will see rhythmic changes in pressure moving downward.
9. Finally, to test the UES, you will be asked to sit up. The catheter is gradually withdrawn to compare the pressure at the UES with that of the esophagus and throat.
10. The catheter is then be gently removed.

Post-Test

Once completed, you will be given a tissue to blow your nose but otherwise will be well enough to return home. You can resume your normal diet and any medications you regularly take. 

After the Test

Side effects of esophageal manometry tend to be minor and may include a mild sore throat, coughing, minor nosebleeds, and sinus irritation.

If your throat is sore following an esophageal manometry test, you can either gargle with salt water or use a benzocaine throat lozenge like Cepacol. The irritation will usually go away in a day or so.

It is also not uncommon to have blocked sinuses and minor nosebleeds. You can often help clear sinuses with an over-the-counter corticosteroid nasal spray or a sterile saline nasal spray. Antihistamines don't usually help since the swelling is due more to inflammation than allergy.

Nosebleeds can be treated by pinching the soft part of your nose above the nostril and breathing through your mouth.

While serious side effects are uncommon, you should call your healthcare provider immediately if you experience any unusual symptoms, including fever, severe reflux, vomiting, arrhythmia, shortness of breath, or bloody sputum.

Interpreting the Results

A few days after the test is performed, your healthcare provider will review the results with you. While the tests can provide valuable insights into how well your esophagus and sphincters are functioning, clinical judgment may be needed to interpret the results. 

At times, the answers may not be so clear. Esophageal manometry is a technically challenging test prone to variables that can sway the results. While the tests may provide irrefutable evidence of a motility problem (such as dysphagia), other conditions (like achalasia) may be far more difficult to pin down.  Clinical experience and expertise are, therefore, central to obtaining an accurate diagnosis.

If you are not fully convinced of what is being told you, do not hesitate to seek a second opinion. Sometimes a fresh set of eyes can add new insights and bring you that much closer to an effective treatment.

A Word From Verywell

If you are feeling nervous about undergoing an esophageal manometry, don't wait until last minute to share these concerns with your healthcare provider or a member of the medical staff.

Sometimes it helps to be walked through the procedure and see what the catheter actually looks like. Knowing what to expect can relieve a lot of the fear.

Try to focus on the benefits and aims of the test. As a relatively fast and safe procedure, the benefits of esophageal manometry will almost always outweigh the downsides.