The modified barium swallow study: What’s it like?

kara larson gets mia ready for her swallow study
(D. McCollister/Boston Children's)

If your child has dysphagia or another swallowing problem, their physician may recommend a “swallow study.” Technically called a modified barium swallow study, this test can help clinicians determine whether a child is aspirating, which means that food or liquid is entering their lungs when they try to eat or drink. “This study is completely voluntary in that we can’t force a child to eat during the test, but it does give us a better picture of whether kids are feeding safely,” explains Kara Larson, a speech-language pathologist in the Aerodigestive Center and Feeding and Swallowing Program at Boston Children’s Hospital.

To learn more, follow along with her patient Mia as she undergoes a modified barium swallow study.

mia and her parents arrive for a swallow study
kara larson gets mia ready for her swallow study
barium formula on table for swallow study
mia's parents feed her during swallow test
clinicians watch the mia's swallow study on screen
larson gives mia's parents her swallow study results

Your child should arrive hungry for a swallow study, so don’t give them anything to eat for two or three hours before the test. “We want to replicate the same feeding scenario at home, so families should bring their child’s usual foods or liquids, their bottle if they use one, and any foods they seem to have difficulty with,” says Larson.


A swallow study typically takes place while your child is sitting up — babies like Mia sit buckled into a car seat-like chair. However, if you usually feed your child while they’re reclined, the clinician will want to mimic that same position during the test. The seat is located in front of a special fluoroscopy, or x-ray, machine, which uses a low dose of radiation to create real-time images of your child’s anatomy. For this reason, your child will wear a protective lead shield during the study.


A swallow study uses a radio-opaque substance called barium to coat the food or liquid your child will consume. This causes it to light up as images on the fluoroscopy machine as it passes from the mouth through the esophagus. Barium has a sweet flavor and is safe to consume. The clinician may thin it out and add it to formula or breast milk, mix the powder to pudding or yogurt, or sprinkle it on food. “We call it ‘frosting’ or ‘magic powder’ to appeal to kids,” explains Larson.


Whenever possible, Larson and her colleagues encourage parents to take part in the test by joining their child and even helping feed them. Because of the exposure to radiation, pregnant women can’t participate. Otherwise, you’ll just need to don a protective lead vest, as Mia’s parents are wearing here. If you have concerns about radiation and your child, a radiologist is available to answer any questions.


The average swallow study takes about 20 to 30 minutes, although it may be shorter or longer depending on your child’s individual situation. This is the total time from when your family enters the x-ray suite until when you leave. The fluoroscopy machine is only turned on when your child is actually swallowing. The staff can see the results in real-time, so families can leave the appointment knowing the outcome. After the test, a clinician will go over the results with you, suggest dietary or positioning recommendations, and collaborate with a Boston Children’s physician if more extensive treatment is needed.


Depending on the results of the test, your clinician will likely send you home with recommendations for further counseling from the Aerodigestive Center, Center for Airway Disorders, Feeding and Swallowing Program, or other care teams. “We usually want to see families back two to four weeks later and then every six to eight weeks so we can see what changes are working,” says Larson.

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Learn more about the Aerodigestive Center and Feeding and Swallowing Program.

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