What tests or investigations are required to diagnose the cause of difficulty swallowing?

In the past, swallowing disorders were difficult to manage because of poor diagnostic tools. However, the last decade or more has seen significant advances in the technologies used to diagnose the cause of dysphagia. This means that now, a clear diagnosis can be made in the majority of such patients.

The tests include one or more of:

Endoscopy: This is usually the first test undertaken to diagnose dysphagia. Under sedation, a camera is inserted through the patient’s mouth to view the pharynx (throat), oesophagus and stomach.

Endoscopy is a good test to rule out cancer, and for identifying structural disorders of the oesophagus and pharynx. At endoscopy, biopsies of the oesophagus should be taken to rule out microscopic inflammatory disorders of the oesophagus which can cause dysphagia.

Oesophageal Manometry: If endoscopy is normal, and especially where a motility disorder of the oesophagus is suspected, the test of choice is oesophageal manometry. This is the gold standard for the diagnosis of oesophageal motility disorders.

Barium swallow: An x-ray test where barium is swallowed and x-rays taken to identify how well the barium passes through while swallowing. It is not as accurate as manometry for diagnosis of oesophageal motor function (motility), but sometimes provides complementary information. It also provides information about the structure of the oesophagus, but in general is not as good as endoscopy in this regard.

Modified barium swallow (video fluoroscopic swallow study): Similar to the barium swallow, but focusing exclusively on the pharynx (throat). This is performed by a speech pathologist. It is the test of choice to diagnose motor disorders of the pharynx.