What a great question! I was at NJH and one day I had a barium test where I ate graham crackers dipped in barium goo and quite a few drinks of barium liquid. While I was swallowing, they took their x-rays. What they are looking for is if the epiglottis was open or close while swallowing. The epiglottis is a flap of cartilage that prevents food or water from entering the trachea during swallowing. The flap is to open during breathing and closed during swallowing. In my case, there was very minimal seepage at the muscles that connect flap. They gave me swallowing exercises that I was to do for 6-8 weeks to strengthen the muscles, which I did. My case was minor, so I didn't need much as for exercises. Also, I don't boil my drinking water. I installed an ultrafiltration system that filters anything above .01 microns. I have to change out the 4 cannisters every 9-12 months. I also drink bottled Icelandic Glacier mineral water, which supposedly doesn't contain mycobacterium-not sure if that's true. There's also the chance of aspirating food or drink by breathing and drinking at the same time, hence it "goes down the wrong way".