In Mexico, if you are disabled you will be treated extremely well, both on exiting and re-entering the country. Ask for a wheelchair. When travelling from the U.S. ask for a wheelchair as it may get you through security that much quicker but do not bet on it. From past experiences, here's what is most likely to happen, as you go through security you will told that you test positive for explosives. By the time they have put you through the 'wringer' you will be ready to explode. While I take security seriously, TSA play games and you may find that you are the object of a training exercise. The giveaway is that you will be escorted to another area and a Supervisor will be overseeing a person who looks and acts like a new employee. The most annoying part of the whole process is the way you are treated, no courtesy whatsoever.