Note: We’ve kept this story pretty much spoiler free with only the most minor scene details, but proceed at your own risk if you want to know absolutely nothing about Avengers: Endgame!
Avengers: Endgame is three hours and one minute long. The average person pees six to eight times a day; some do it 10 times a day. Do the math and chances are you might need to pee (or poo) during this cinematic event you paid $15.50 to get into.
So here’s a tip: Empty out your system before the movie. If you don’t get the chance to do it in the comfort of your own home, you’ll likely have about 15 minutes of previews before the movie starts to build a log cabin at the theater.
Source: IGN.com Avengers Endgame: The Best Time to Use the Bathroom