FAA Shutdown Sparks Bathroom Chaos, Passengers Face Long Lines

The nationwide FAA shutdown has gone from a ground stop to a full-blown bathroom bottleneck ... and things are about to get real real!!

Sources at LAX tell TMZ that passengers waiting at the airport were told to use the bathroom and get food ... because the airport was preparing for an influx of landing flights.

TMZ obtained video from LAX on Friday showing passengers standing in long restroom lines ... as travelers scramble to take care of business before a flood of arriving passengers turns the toilets into a total traffic jam.

And with planes stuck on the tarmac amid the nationwide shutdown, things could really start to stink for arriving passengers ... 'cause once those floodgates open, the s***'s really gonna hit the fan!

As we reported ... the Federal Aviation Administration issued an extremely rare nationwide ground stop Friday, ordering departing flights across the country to remain grounded until further notice over safety concerns.

U.S. Transportation Secretary Sean Duffy said the sweeping shutdown was triggered by a communications issue affecting all Air Route Traffic Control Centers ... with FAA technicians scrambling to investigate the problem.

The FAA also said inbound international flights would be handled on a case-by-case basis ... leaving travelers across the country dealing with major uncertainty.