last trip at christmas DFW and PHL they showed me the screen when i sighed and ask what the issue is. they assured me it's not my belt. which i did take off 2nd trip and the screen showed lower box to be searched. so does someone sit in a back room and press the button where they want searched and do this as a joke. they couldnt tell me the real reason for the search, just that area is required to be searched because of what is on the screen.

been wearing the same pair of jeans on flights for a year now. and yes i do wash them lol. not necessarily the day before i fly..but maybe i should?

so can they really not tell 'why' that area is of interest (chemical/physical etc?)

in addition to the expected jokes id really like to know how to avoid this.

would getting pre check help me out? i only fly DFW and PHL but i never looked at precheck. do they only have metal detectors for precheck?