Brief Answer: tests will be needed Detailed Answer: Hi, i will try to help. What could be happening is that your food is not going all the way down into the stomach and getting stuck in the esophagus. saliva and fluids turn in to bubbles / foam, and if they don't make it to the stomach quickly it will come back up through the mouth. You don't seem to describe a problem to transfer food from you mouth down to your esophagus. In any case, what you describe is definitely not normal, and there could be many explanations for this. The most common is a motility problem of the muscles of your esophagus / stomach. This can be checked with an "Esophageal manometry", however not many people do this particular test, and usually other tests are performed first before getting to the manometry. This includes either an upper endoscopy to directly visualize with a camera your mouth, esophagus and stomach. This is important to make sure you don't have a tumor or narrowing causing your symptoms. An alternative is an Xray test called "upper GI series" in which you have to swallow a liquid contrast, and while the contrast is going down they will take some x rays of your neck/chest area to see how the contrast goes down, and see if there is anything blocking. The above tests should provide enough information to provide an answer to your symptoms. A Gastroenterologist would be able to help you get the studies done. Hope that helps. let me know if you have any further questions or concerns

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