What Is the Difference Between VFSS & MBS?

According to the American Speech-Language-Hearing Association, a VFSS (videofluoroscopic swallowing study) and an MBS (modified barium swallow) are two terms that mean virtually the same thing -- a tool to tell your speech language pathologist how well you swallow. The different names are used by different pathologists and clinics, but the concept and the test are the same.

How the Test Works

• You'll be in the radiology department of the clinic or hospital running the test. Your speech language pathologist will already have some prepared drinks or foods containing barium. The purpose of the barium is to light the substances up on an X-ray. While you're swallowing, a radiology technician will be X-raying your body. You'll likely have foods and drinks of different textures and in different amounts, with your head in different positions.

What the Test Does

• By seeing what happens to food and drinks when you swallow them, the pathologist can identify weak areas in your swallowing muscles. This will help her identify areas that need attention in therapy, because many of those muscles are also the ones you use to form words. Also, if you have real trouble with certain items, the pathologist will recommend staying away from food or drinks with that texture.

People Who Can Test

• Adults, children and even infants can undergo an MBS/VFSS. If your child is very young, you may want to hold him on your lap to comfort him during the test. Depending on your child's specific needs, the pathologist may have particular instructions for his test.

Health Risks

• Swallowing barium is not harmful and barium will pass through the body quickly. While X-rays do expose the body to radiation, the machine is only on during swallowing, so exposure will be minimal.