Hi, haven't you been checked out for Eosinophilic Esophagitis? That won't show up on any scan, they have to do a biopsy by taking small snips with an endoscope. It's caused by certain immune cells running amok: eosinophils and mast cells. It's an 'emerging disease', i.e. it's known only fairly recently.
See if this sounds like you:
...not only the symptoms but also it being mistaken for GERD. If you get food stuck in your esophagus then there is not much doubt.
While radiation exposure is something we should all consider prior to testing, it is highly improbable that your health has been compromised by your diagnostic imaging. It is extremely difficult to reach dangerous dose levels from diagnostic medical radiation. A CT of your abdomen one time has more radiation that all 3 of your barium swallows. It would be statistically improbable that radiation exposure has anything to do with your current problem. I think any worries involving radiation are not warranted. While there could be numerous things causing your symptoms, you can cross radiation exposure off the list. It is always best to find a healthcare provider that can clinically correlate your symptoms with your diagnostic imaging and lab work. I wish you all the best!
"But I am concerned about five years of GERD combined with three upper GI swallow tests producing cancer in my esophagus."
Samuel, there's enough disagreement about the danger from radiation in scans so that I personally wouldn't be happy with having so many of them -- especially at the young age of twenties, because there are many more years of life for a problem to eventually arise.
But did the scans plus GERD cause you to have esophageal cancer? Not as of May, or the barum x-ray would have likely seen it.
Yes, you're right that GERD can cause Barrett's Esophagus, which can lead to cancer. But the eventual risk of cancer is small that way. Besides, you likely don't even have Barrett's (yet), or the scoping would have seen that.
Yes, in late stages, esophageal adenocarcinoma (cancer) could spread enough to cause chest pain; but you don't even have minimal signs of cancer at this point, and Barrett's doesn't usually cause pain.
Besides considering the odds with Barrett's, there is also the time delay. This one study says that it takes ~25 years of having Barrett's to get cancer.
"The minimal incubation period from the onset of Barrett's oesophagus to symptomatic adenocarcinoma"
(I haven't seen anything, however, on the risk of combining GERD with radiation.)
Though cancer is more or less ruled out so far, you certainly can't just let this go on as is for more years. You don't want to be on PPI drugs forever, either. I think that Eosinophilic Esophagitis does fit your symptoms (nothing will fit exactly), especially since they have a mysterious cause. If not EoE, then here is a DDx that fits less well:
If you are still concerned about cancer, you could ask for a scoping to get some cells for biopsy - to see if they look pre-cancerous under the microscope. I'd say they should also then look for eosinophils. Another type of immune cells called mast cells would also be involved.
As far as your chest pain, is that just in the vertical center line or does it go out into the lungs on both sides?