Fiberoptic Endoscopic Evaluation of Swallowing (FEES) is a gold standard instrumental swallowing assessment performed by a licensed speech-language pathologist.

A small flexible endoscope is passed transnasally to view the hypopharynx and laryngopharynx. Various consistencies of food and liquid are prepared and dyed with food coloring to improve visibility as the bolus travels through the throat. The swallowing mechanism is observed in real-time as the patient swallows the foods and liquids.

This allows the speech pathologist to objectively evaluate the anatomy and pathophysiology of the swallowing mechanism. The speech pathologist may trial therapeutic maneuvers and interventions to improve swallow efficiency and safety.