Learning About Videofluoroscopic Swallow Study (VFSS) for Adults

A videofluoroscopic swallow study (VFSS), also called a modified barium swallow, uses a type of x-ray (fluoroscopy) video to see what happens when you swallow food and liquid.

A VFSS takes pictures of your mouth and throat (esophagus) while you swallow food and liquid. A VFSS is done by a speech-language pathologist or an occupational therapist, with a radiologist and a radiology technologist. The x-ray video itself takes about 5 minutes. You should plan for the visit to take at least an hour. This gives time to ask questions and to discuss the results and any recommendations.

The VFSS helps to see:

• if there are problems with the mouth or throat making eating difficult
• whether food or liquid is entering the airway (trachea). This is called aspiration.
• what might help to manage or treat the problem

The VFSS uses barium. Barium is a chalky-tasting material that is mixed with food and liquid. When you swallow the food or liquid mixed with barium, it can be seen in the x-rays.

Why is it done

A VFSS is done for eating and swallowing problems with the mouth or throat. You might have a problem with your mouth or throat if you have symptoms like:

• coughing or choking when you eat or drink
• a wet-sounding voice
• breathing changes when you eat or drink
• lots of chest infections

A VFSS helps you and your healthcare provider talk about your treatment options.

How to prepare

Before the VFSS, tell your doctor or healthcare provider if you:

• have any allergies (especially an allergy to barium)
• are pregnant (or think you might be)
• have been sick (vomiting)
• have diabetes

Preparation instructions for adults:

• You can eat, drink, or have a tube feeding right up until the VFSS.
• If your healthcare provider tells you not to eat or drink anything before the VFSS, follow their instructions.

Before the VFSS

• Remove any clothing or jewelry that is in the areas where the x-rays will be taken (like a scarf, necklace, or earrings).

During the VFSS

You will sit like you normally do to eat or drink. You'll be asked to drink and eat small amounts of food and liquid that have been mixed with barium. You may also need to swallow a barium pill.

You may be asked to move into different positions to eat and drink during the VFSS.

After the VFSS

After the VFSS is done, you can resume your regular activities. Talk to your healthcare provider about what to eat or drink.

Risks

• You'll be exposed to a small amount of radiation during the VFSS. The x-ray uses a small amount of radiation that’s within safety limits. If you have concerns, talk to your healthcare provider.
• For the VFSS, you’re given small amounts of food and liquid to lower the risk of anything significant getting into your airway. You can ask for the VFSS to be stopped at any time.
• If barium gets into your lungs, it is not harmful.
• Reactions to barium are extremely rare and are usually very mild. Reactions can include swelling of the upper airway and low blood pressure. If these reactions occur, they are treated right away.

To prevent constipation from the barium, drink extra fluids for 1 to 2 days after the VFSS.

When you should call for help

After the VFSS, call your healthcare provider if you have:

• stomach cramps
• trouble having a bowel movement for 2 to 3 days after the VFSS

If you need health advice any time, day or night, call Health Link at 811.

To see this information online and learn more, visit MyHealth.Alberta.ca/health/aftercareinformation/pages/conditions.aspx?hwid=custom.ab_swallow_study_vfss_inst.

For 24/7 nurse advice and general information call Health Link at 811.

Current as of: June 6, 2026

Author: Diagnostic Imaging, Alberta Health Services and Speech-Language Pathology, Allied Health Professions

This material is not a substitute for the advice of a qualified health professional. This material is intended for general information only and is provided on an "as is", "where is" basis. Although reasonable efforts were made to confirm the accuracy of the information, Alberta Health Services does not make any representation or warranty, express, implied or statutory, as to the accuracy, reliability, completeness, applicability or fitness for a particular purpose of such information. Alberta Health Services expressly disclaims all liability for the use of these materials, and for any claims, actions, demands or suits arising from such use.