A swallowing study, also known as an instrumental assessment of swallowing, is a medical procedure used to evaluate the function and mechanics of a person’s swallow. This diagnostic tool provides healthcare professionals with an objective view of how food and liquid move from the mouth through the throat and into the esophagus. It is typically performed when a patient is suspected of having dysphagia, the medical term for difficulty or discomfort in swallowing. By visualizing the swallowing process in real-time, the study helps identify the specific physiological breakdown causing the problem and determine the safest way for the patient to eat and drink.
Symptoms That Lead to a Swallowing Study
The need for a swallowing study is often indicated by patient-reported experiences suggesting a disruption in the normal mechanics of eating. Common signs include frequent coughing, choking, or throat clearing during or immediately after meals. These reactions signal that food or liquid may be entering the airway, a process called aspiration or penetration.
Patients may also describe a persistent sensation that food, liquid, or a pill is getting stuck in the throat or chest. Less obvious indicators include unexplained weight loss or dehydration, resulting from avoiding meals or an inefficient swallow that prevents adequate nutrient intake. A wet or gurgly vocal quality immediately following a swallow suggests that material is lingering around the vocal cords. Repeated episodes of aspiration pneumonia can also point toward a silent swallowing problem where material enters the lungs without triggering a cough reflex.
The Two Primary Diagnostic Methods
When a swallowing problem is suspected, a Speech-Language Pathologist (SLP) may recommend one of two primary instrumental studies: the Modified Barium Swallow Study (MBSS) or the Fiberoptic Endoscopic Evaluation of Swallowing (FEES). These tests are complementary, each offering a distinct perspective on the swallowing mechanism.
Modified Barium Swallow Study (MBSS)
The MBSS, also called a Videofluoroscopic Swallowing Study (VFSS), uses X-ray technology to capture a moving image of the swallow. During the procedure, the patient consumes different types of food and liquid mixed with barium, a contrast material that appears white on the X-ray screen. This allows the clinician to see the entire path of the food bolus, from the oral phase through the pharyngeal phase and into the upper esophagus. The MBSS is typically performed in a hospital’s radiology suite and is time-limited to reduce the patient’s exposure to radiation.
Fiberoptic Endoscopic Evaluation of Swallowing (FEES)
The FEES involves passing a thin, flexible endoscope through the patient’s nose to position the camera just above the voice box (larynx). The patient swallows dyed food and liquids while the clinician views the pharyngeal structures on a monitor in real-time. A major advantage of FEES is its portability, allowing it to be performed at the patient’s bedside without the need for a specialized X-ray suite or radiation exposure. While the MBSS provides a full view of the oral and esophageal stages, the FEES offers clearer, direct visualization of the pharynx and larynx before and after the swallow, and can be repeated safely to monitor fatigue or treatment effectiveness.
Analyzing the Findings and Treatment Recommendations
The data collected from the instrumental study is analyzed to determine the nature of the swallowing impairment and inform a plan of care. Clinicians look for two primary safety concerns: penetration and aspiration. Penetration occurs when material enters the laryngeal vestibule above the vocal folds, while aspiration is the more serious event where material passes below the vocal folds into the trachea and lungs.
Efficiency is also evaluated by looking for pharyngeal residue—food or liquid that remains in the throat after the swallow is complete. The study helps pinpoint the exact physiological reason for these issues, such as a weak tongue base, delayed swallow reflex, or reduced laryngeal elevation. This objective information translates directly into specific therapeutic recommendations, often overseen by an SLP.
Treatment plans are highly individualized and may involve modifications to the patient’s diet to ensure safety, such as thickening liquids or altering the texture of solid foods. Compensatory strategies are also taught, which are temporary adjustments made during the swallow (e.g., the chin-tuck maneuver or a head turn) to redirect the food bolus and protect the airway. For long-term improvement, rehabilitative swallowing exercises are prescribed to strengthen specific muscle groups and improve swallow coordination.