Resources
Many people who experience frequent or severe acid reflux are recommended to take a diagnostic test by their clinician or gastroenterologist, especially if the person is not responding well to lifestyle adjustment, diet changes, or medication. These tests help determine how severe the reflux is, whether the esophagus has been damaged, and what type of treatment may work best. Understanding what each test involves can make the process less intimidating for the patient.
GERD, just like other gut conditions, can look different from person to person. Some people mainly experience heartburn, while others have different symptoms. Diagnostic tests help clinicians answer questions like:
• Is the esophagus inflamed or damaged?
• Are there structural issues contributing to reflux?
• Is the lower esophageal sphincter (LES) functioning properly?
• Are there any other potential gut conditions?
• Is acid directly causing symptoms?
A proper diagnosis helps your care team tailor a plan that better fits your reflux history.
An upper endoscopy, also referred to as an upper gastrointestinal endoscopy, is one of the most common and useful tests for evaluating GERD. It is used to examine the upper part of the digestive system, which includes the stomach, esophagus, and first part of the small intestine.
What it is
In the procedure, a thin, flexible tube with a tiny camera is inserted through the mouth. It enables the specialist to see any potential signs or damage first-hand.
What it can show
Upper endoscopies are common for a reason. They show things like:
• Barrett's esophagus
• Hiatal hernias
• Esophageal inflammation or irritation
• Ulcers
• Erosive esophagitis
• Structural changes
What to expect
Patient receive a sedation to help them relax and stay comfortable. The procedure is quick, and usually last 10 to 20 minutes. It is almost always painless, although it is common to experience some discomfot afterwards, such as a shore throat.
An endoscopy is especially important if a person has trouble swallowing, long-term symptoms, or persistent discomfort.
pH monitoring measures how often stomach acid enters the esophagus, as well as how long it stays there. It is one of the most accurate ways to diagnose GERD. There are several types:
1. Catheter-based pH test
In this test, a thin tube is inserted through the nose and into the esophagus. The patient's nose and throat are typically numbed with a spray. It then stays in place for 24 hours and measures acid levels during normal daily activities- one can still drink, eat, and do most regular things.
2. Wireless pH capsule test
In this test, a small capsule is attached to the lining of the esophagus, usually in combination with an endoscopy. The capsule records acid exposure over 2-4 days, and send the data wirelessly to a receiver that is carried by the patient. The capsule then detaches on its own and is passed naturally.
What to expect
Patients are normally expected to keep a symptom diary and record when they eat, lie down, or experience discomfort. This helps the specialist match reflux symptoms to acid events.
pH monitoring tests are especially helpful when symptoms are unclear or when one wants to know whether medication is truly helping.
An esophageal manometry evaluates how well the muscles in the esophagus work, and how effectively they move food downward.
What it is
In the test, a thin tube with sensors is inserted through the nose and into the esophagus. The patient swallows small sips of water while the test measures pressure and muscle contractions.
What it shows
This tests can show things like:
• Lower esophageal sphincter function
• Coordination of esophageal muscles
• Any motility disorders that can mimic or worsen GERD
What to expect
The esophageal manometry test is brief, and typically contains around 10 minutes of active measuring. While the test is not painful, it can feel strange or temporarily cause mild discomfort.
Manometry is often done before pH monitoring, or before considering certain other procedures for GERD.
A barium swallow is an imaging test that helps visualize the shape and movement of the esophagus and stomach.
What it is
The patient drinks a liquid containing barium, which then coats the digestive track. As the patient swallows, X-rays are taken.
What it shows
This test can show things like:
• Narrowing of the esophagus
• Hiatal hernias
• Structural abnormalities
• Swallowing coordination problems
What to expect:
A barium swallow test is noninvasive and painless. Patients may experience mild constipation afterwards, so drinking extra water is often suggested. While it cannot diagnose GERD by itself, the test can reveal problems that contribute to acid reflux or mimic its symptoms.
Impedance testing is often performed alongside pH monitoring. It has become more common in recent years, since it can detect more events and provide a more complete picture than older tests.
What it is
Similar to pH monitoring, a thin catheter is used to measure both acidic and non-acidic reflux events.
What it shows
This test shows things like:
• How often stomach contents travel upward
• How long reflux episodes typically last
• Whether non-acidic reflux contributes to symptoms
Esophageal impedance testing is helpful for those whose symptoms persist even with acid-reducing medication like PPIs.
A person's clinician or specialist will choose the right test based on one's symptoms, medical history, and goals. For instance:
• Frequent heartburn may be checked with an endoscopy
• Atypical symptoms like coughing or throat issues may be checked with pH monitoring
• Swallowing difficulties may be checked with a manometry or a barium swallow
• Symptoms that have persisted even with medication may be checked with impedance testing
Preparation varies by test, but common steps include:
• Avoiding food and drink for several hours before an endoscopy
• Pausing some medications, such as PPIs or H2 blockers
• Wearing loose and comfortable clothing
• Bringing a symptom log or list of questions
Make sure to follow any instructions from the clinician or specialist carefully.
Once the results are in, the clinician or specialist will review the results with the patient and explain what they may mean for their treatment plan. Depending on the findings, recommendations may include things like:
• Lifestyle and diet changes
• Medication adjustments
• Additional testing
• Treatment for complications
• Consideration of non-surgical or surgical options for severe GERD
A clear diagnosis will help guide the most effective next steps. Read more about the treatment process for GERD and acid reflux here.
