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A number of different tests can be performed to assess people with achalasia, to look for other common causes of the same symptoms and make a definite diagnosis.

Upper GI endoscopy

The first test to investigate difficulty in swallowing is usually an upper GI endoscopy (often referred to as an OGD). This is a common procedure involving the insertion of a thin tube with a camera on the end through the mouth into the oesophagus, stomach and first part of the small bowel called the duodenum. This test is important to look for signs of achalasia as well as to look for other problems such as acid damage or oesophageal cancer. It is a very routine procedure, but as with any test there are benefits and risks, even though the risks are very low. More information on this procedure, its benefits and risks are available here.

Contrast swallow

This test may also be called a barium swallow and is often combined with a meal test to examine the stomach as well as the oesophagus. It involves drinking some fluid (called barium) and having x-ray pictures taken of the fluid going down the oesophagus into the stomach. This is a good test of how the oesophagus squeezes and is very helpful in making a diagnosis of achalasia (see figure 1).

Achalasia barium 1

Figure 1. Appearance of achalasia on barium swallow. Source: UHBW NHS Foundation Trust, 2021.

pH and manometry

These two tests (pH testing and manometry) are often combined to assess a range of symptoms. They involve passing a fine tube through the nose into the oesophagus, then doing a series of swallowing tests to measure how the oesophagus works (the manometry part of the test). A tube is then left in place for 24 hours and you go home with this before having it removed the following day (pH testing). During this period, you can record symptoms that you experience which can then be looked at together with measurements from the tube.