Test Overview

Esophagus tests measure muscle pressure and movement, coordination, and strength of the tube that connects the throat to the stomach (esophagus). They test how well the ring of muscles (sphincters) at the top and bottom of the esophagus work. Esophagus tests also measure the movement and volume of gas, liquid, and solid through the esophagus and its pH (acid or non-acid). See a picture of the esophagus.

The most common esophagus tests include:

• pH monitoring (esophageal acidity test), which measures the acid content (pH) in the esophagus. A low pH for long periods may mean frequent abnormal backflow (reflux) of stomach acid into the esophagus (gastroesophageal reflux disease, or GERD).
• Esophageal manometry, which measures the strength and pattern of muscle contractions in the esophagus. This test can find:
  • Weakness in the lower esophageal sphincter (LES), which allows acid to reflux into the esophagus.
  • Weak muscle contractions during swallowing that slow the rate at which food or stomach acid is cleared from the esophagus.
  • Abnormally strong contractions (spasms) that can cause chest pain or the sensation that food is stuck after swallowing (dysphagia).

Either pH or manometry testing can be combined with a test that measures the movement and volume of gas, liquid, and solid through the esophagus (multichannel intraluminal impedance testing, or MII). When MII is combined with manometry (MII-EM), it can show how the muscles of the esophagus are contracting when there is food or liquid in the esophagus. When MII is combined with pH testing (MII-pH), it can detect reflux from the stomach into the esophagus and measure both the volume and the acidity.