FEES stands for Fiberoptic Endoscopic Evaluation of Swallowing. It’s a diagnostic test used by speech-language pathologists (SLPs) to watch your throat in real time while you swallow, helping identify problems that make eating, drinking, or managing saliva difficult. The procedure involves passing a thin, flexible tube with a tiny camera through your nose and down into your throat, where it captures video of the structures involved in swallowing.
What FEES Is Used For
FEES is one of two main instrumental tests available for evaluating swallowing disorders, known clinically as dysphagia. The other is a modified barium swallow study, which uses X-ray imaging. FEES is often the preferred option because it doesn’t involve any radiation, it’s portable enough to be done at a patient’s bedside or in an outpatient clinic, and it gives a direct, close-up view of the throat’s soft tissue.
You might need a FEES test if you’ve had a stroke, a head or neck injury, or head and neck cancer. It’s also commonly used for people with progressive neurological conditions like Parkinson’s disease, ALS, multiple sclerosis, or Alzheimer’s disease and related dementias. Conditions that reduce saliva production, such as Sjögren syndrome, or structural blockages in the esophagus can also warrant the test. Even without obvious symptoms, people at high risk for swallowing problems may be referred for FEES as a precaution.
Common symptoms that prompt a referral include a feeling of food getting stuck in your mouth or throat, coughing or choking during meals, a wet or gurgly voice after eating, unexplained weight loss, or pain while swallowing.
How the Procedure Works
A speech-language pathologist performs the test, sometimes alongside a physician depending on the setting. Before starting, a numbing spray is typically applied inside your nose so you don’t feel much discomfort as the endoscope is inserted. The endoscope itself is a thin, flexible tube with a light and a small camera at the tip. It’s guided gently through your nasal passage, past the back of your throat, and positioned above or near your voice box.
The test has two basic phases. First, the SLP observes the structures of your throat at rest, checking how well your vocal cords move, whether secretions are pooling in areas where they shouldn’t be, and how the muscles of your throat are functioning overall. The camera can be positioned at different levels to examine specific areas: higher up to look for buildup in the pockets at the base of the tongue and around the voice box, and lower to assess how well the voice box closes during coughing and swallowing.
In the second phase, you’ll be asked to eat and drink small amounts of food and liquid in various textures, from thin water to thicker consistencies and soft solids. These are often dyed with food coloring so they show up clearly on the video screen. The SLP watches how the food moves through your throat, whether any of it enters your airway, and whether residue gets left behind after you swallow. This information helps determine what food textures are safe for you and whether specific swallowing strategies could help.
One thing FEES can’t capture is the exact moment the swallow reflex fires. When the throat muscles squeeze around the food, the camera briefly loses its view because the tissue presses against the lens. Clinicians call this the “white-out” phase. It’s a known limitation, but the before and after views provide plenty of diagnostic information.
What It Feels Like
The test is generally quick. The actual evaluation typically takes around 15 to 20 minutes, though the total appointment may be longer if preparation or discussion is involved. Most people describe the sensation as unusual but tolerable. The numbing spray helps reduce discomfort from the tube, though you may feel a mild pressure or tickle as the endoscope passes through your nose. You’re awake throughout and able to follow instructions.
No special dietary preparation is usually needed. If the test is being done for a child, parents are often asked to bring familiar feeding items like a favorite cup, bottle, or spoon so the evaluation reflects how the child normally eats.
Safety and Risks
FEES is considered very safe. A large retrospective study of 964 consecutive exams found an overall complication rate of just 1.14%. The most common issues were brief episodes of vomiting (3 cases) and laryngospasm, a temporary tightening of the vocal cords that occurred in 4 cases, or about 0.4% of the time. Only one patient experienced a nosebleed, which stopped on its own without treatment. Some patients simply couldn’t tolerate the sensation and the test was ended early, which accounted for most of the minor complications.
FEES vs. Modified Barium Swallow
The other widely used swallowing test is the modified barium swallow study (MBSS), sometimes called a videofluoroscopic swallow study. During an MBSS, you eat food mixed with barium (a contrast material) while an X-ray machine records your swallow from the side. Each test has strengths that make it better suited for different situations.
FEES gives a direct, detailed view of the throat’s soft tissue, making it especially good for detecting pooled secretions, subtle vocal cord problems, and tissue changes from conditions like acid reflux or tumors. It uses no radiation, so it can be repeated as often as needed without exposure concerns. It’s also portable, which makes it practical for patients in intensive care, nursing homes, or home health settings who can’t easily travel to a radiology suite.
The MBSS, on the other hand, shows the entire swallow sequence from the mouth through the upper esophagus, including that brief moment FEES misses during the white-out phase. It’s better for evaluating how the mouth prepares and moves food, and for observing the opening of the upper esophagus. The choice between the two often depends on the specific clinical question, the patient’s mobility, and what’s available at the facility.
Who Performs FEES
FEES is typically performed by a speech-language pathologist with specialized training in the procedure. The American Speech-Language-Hearing Association (ASHA) does not require a separate specialty certification, but clinicians are expected to demonstrate competency. State regulations vary. Some states mandate a specific number of supervised endoscope passes before an SLP can practice independently, while others leave it up to the workplace to set its own policies. In some settings, a physician may need to be present or available during the exam.
Even after completing an intensive training course, many SLPs report needing months of supervised practice before feeling fully confident performing the procedure on their own. This extended learning curve reflects the skill required to handle the endoscope, interpret the video in real time, and make accurate clinical judgments about swallowing safety.