Actually a contact in Homeland Security warned me ahead of time that based on what he knows of the TSA field people, I would have to put the Jevity down the tube, so I was prepared mentally.
Again, it's the sealed cans that drive them crazy, not the PEG. It just that in the past, I've had three and four hour delays on planes taking off and then up to a five hour flight and then delays on landing so we felt I should bring the cans. And once you open the pop top can of Jevity in the airport line, what are you going to do with it? Next time I may bring more and just throw the darn open can out in the trash or tell TSA they can keep it as a souvenir or perhaps in lieu of a tip.
And of course, you are right that a feeding tube does not pose any security problem, but then neither does a 4 oz tube of sunscreen or antiseptic cream which is banned instead of the 3 oz version. Wouldn't want to upset terrorist countries by actually profiling terrorists instead of randomness now would we?