jkhuggins

And I'll stop you right there. At that point, your son's chocolate milk is not a beverage for a child. It's a medically-necessary liquid, at which point a different set of rules applies:

http://www.tsa.gov/traveler-informat...essary-liquids

According to that site, such liquids in excess of the 100ml limit may necessitate additional screening, which might include a patdown.

Of course, it is regrettable that some airports perform the patdown and others do not, and there's no way for an ordinary passenger to know what the proper expectation should be.