Upper GI Tract Tests
In addition to upper endoscopy and upper GI series, other tests to examine the upper digestive tract include:
- Capsule endoscopy
- Esophageal manometry
- pH monitoring
- Esophageal impedance testing
- Duodenal gastroesophageal reflux testing
An upper endoscopy does not provide information about the small intestine beyond the duodenum. For this, the U.S. Food and Drug Administration (FDA) approved the use of a tiny ingestible camera in a capsule that takes close-up pictures of the small intestine as the capsule moves through the digestive tract. (An ingestible camera is also approved for esophageal endoscopy.)
This test measures pressure and evaluates contractions in the esophagus. It is typically performed to diagnose gastroesophageal reflux disease (GERD) and swallowing problems. During the test, a physician or specially trained technician inserts a thin, pressure-sensitive probe through the nose and into the esophagus to measure pressure in the esophagus while it contracts; it also measures pressure of the lower esophageal sphincter.
Abnormal muscle contractions in the esophagus and decreased lower esophageal sphincter pressure indicate weakening of the antireflux barrier. The test takes about an hour.
A pH monitoring test is often given to determine if acid is refluxing from the stomach into the esophagus and causing heartburn and GERD. A tiny tube or wireless capsule is placed in your esophagus for 24 hours, while you go about your daily activities, to record fluctuations in acid backing up into your esophagus from your stomach. At the end of the tube is a sensitive probe that detects fluctuations in acidity. Two-day pH monitoring can detect GERD more accurately than standard 24-hour pH monitoring.
The standard test involves a thin tube that is threaded through your nose, which can make it difficult to move about. Another version of the test that does not involve the nose tube is the Bravo test, which is a capsule that attaches to your lower esophagus during an endoscopy. The capsule detaches by itself after about a week.
Both tests also involve a small receiver that records information from the probe. There are also buttons on the receiver that correspond to certain symptoms you may have; pressing them when you have symptoms will record additional information about your condition.
Esophageal Impedance Testing
This test also involves having a tiny tube inserted into your esophagus and measures whether gas or liquid is backing up into the esophagus. It is a helpful diagnostic tool for those with non-acidic reflux, since these substances wouldn't be detected by pH monitoring.
Duodenal Gastroesophageal Reflux Testing
Duodenal gastroesophageal reflux (bile reflux) can be a complicating factor in GERD. This test detects whether contents of the duodenum, such as bile or pancreatic enzymes, are backing up into the esophagus. You go about your daily activities while wearing a tiny tube in your esophagus. The attached fiberoptic tool detects the yellow color of bilirubin, the major component of bile.