Researchers found the number of emergency room visits for toilet-related injuries to the penis, while still rare, increased by about 100 visits each year between 2002 and 2010.
Usually, the injuries happen when boys are learning how to urinate into the toilet while standing up and the seat falls unexpectedly - although a few adults did get snagged by the seat, too.
"It's a toddler basically potty training who doesn't have the most advanced motor skills and they just don't have the reflexes to move fast enough," said Dr. Benjamin Breyer, the study's lead author from the University of California, San Francisco.
Previously, the researchers found that about 16,000 men and women are sent to U.S. emergency rooms (ERs) with genital injuries every year.
Breyer's team was "pretty surprised" to learn that one in 30 genitourinary injuries showing up to the ER involved toilets....
....About 68 percent were so-called crush injuries, which is when the penis gets trapped between the seat and the bowl. Of those, about 97 percent were in children seven years old and younger. Only five adults were caught by falling lids.
Image: Toilet seat, via Shutterstock