US physicists have studied the fluid dynamics of urine "splashback" to help men and women improve their accuracy.

The team from Brigham Young University's Splash Lab filmed a jet of liquid entering a body of water similar to a toilet.

"The amount of splash is considerable, as the repeated impact of the urine droplets opens up a large and interesting cavity," the researchers said.

"Splash is formed both from the initial impact and the collapse of this cavity. The process repeats itself over and over, creating a real mess."

Video: Prof Tadd Truscott and Randy Hurd, BYU Splash Lab