Let’s be honest — people have a habit of bringing their phones to the bathroom. I’ve been guilty of it myself, and chances are that someone is on the toilet reading this article right now. A three-minute trip to the loo can easily turn into 15 minutes of reading, scrolling and posting.

It might seem a harmless way to pass the time when you’re going number two. However, experts warn that what they call prolonged sitting on the toilet can harm your health. It’s even been connected to an increased risk of hemorrhoids and weakened pelvic muscles, said Dr. Lai Xue, a colorectal surgeon at the University of Texas Southwestern Medical Center in Dallas.

“When patients present to me with complaints, one of the main areas we have to delve deeply into is spending a lot of time on the toilet,” Xue said.

Here’s what is going on when you overstay your toilet time.

Potty problems from sitting too long

People should spend an average of five to 10 minutes on the john, according to Dr. Farah Monzur, an assistant professor of medicine and director of the Inflammatory Bowel Disease Center at Stony Brook Medicine on Long Island, New York.

Why is it a problem if you stay longer? First, here’s a short physics lesson. Gravity keeps us grounded on Earth, but that same gravity also forces the body to work harder to pump blood back up to the heart, Xue said.

The open oval-shaped toilet seat compresses the buttocks, keeping the rectum in a lower position than if you were sitting on the couch. With gravity pulling the lower half of the body down, the increased pressure affects your blood circulation.

“It becomes a one-way value where blood enters, but blood really can’t go back,” Xue said.

As a result, the veins and blood vessels surrounding the anus and lower rectum become enlarged and engorged with blood, increasing the risk of hemorrhoids.

Don’t force it either

Forced straining can also increase the pressure to allow hemorrhoids to build. People scrolling on their phones on the toilet tend to lose track of time, Monzur said, sitting and straining their muscles to get a bowel movement out.

And guess what? Your doctors can tell. “Nowadays, we’re seeing an increase in people passing more time on the toilet, and that is very much unhealthy for the anorectal organs and the pelvic floor,” Xue added.

In addition to weakened anal muscles and forced straining, Monzur said sitting on the toilet bowl for too long can also increase the risk of rectal prolapse. A rectal prolapse is when the rectum, part of the large intestine, slips down and bulges out of the anus.

The pelvic floor muscles are another type of muscle weakened from prolonged toilet sitting. Xue explained that pelvic floor muscles coordinate a significant amount of bowel movement and work with the rest of the body to ensure stool comes out smoothly. The gravitational pressure on the pelvic floor strains the muscles when constantly sitting for long periods.

Be more mindful of bathroom time

To avoid spending too much time on the porcelain throne, Dr. Lance Uradomo, an interventional gastroenterologist at City of Hope Orange County in Irvine, California, advised keeping phones, magazines and books out of the bathroom.

“You don’t want to go with the mindset that you will be there for a long time. Because then you’ll want to bring something to keep the mind occupied,” Monzur said. “Make sitting on the toilet bowl as uninteresting as possible.”

If you’re having trouble relieving yourself, Xue advised quitting after 10 minutes. Instead, walk around a bit — since the motion can stimulate gut muscles to produce a bowel movement. Xue also recommended getting hydrated and eating high-fiber foods such as oats and beans to produce regular bowel movements and avoid straining.

Need to know how much? The National Academy of Medicine recommends 2.7 to 3.7 liters of water daily. Additionally, the US Department of Agriculture recommends 14 grams of fiber for every 1,000 calories of food. Xue said that fiber and water soften the stool, making it easier to pass.

Long bathroom times and colorectal cancer

There are situations, however, in which people have to spend an unusual amount of time on the toilet. Constant difficulty or discomfort when passing stool can be a symptom of gastrointestinal issues, such as irritable bowel syndrome and Crohn’s disease.

Worsening constipation or a need to sit on the toilet for a long time may also be a sign of cancer. “If a growth inside the colon grows big enough, it can block the flow of your stool, which can cause constipation and bleeding,” Uradomo said.

The American Cancer Society recently reported an increase in colorectal cancer rates among people under age 55 since the mid-1990s, and the nonprofit estimated there would be 106,590 new cases of colon cancer and 46,220 new cases of rectal cancer this year.

In Uradomo’s career, he’s recalled more young people talking to him about hemorrhoids and constipation and later being diagnosed with rectal cancer.

If you’ve had these symptoms of constipation or sitting on the toilet for a long time for more than three weeks, Monzur said it might be time to bring your concerns to your doctor. Depending on the severity of the symptoms, your primary care doctor can refer you to a gastroenterologist or a colorectal surgeon for a closer look.

Jocelyn Solis-Moreira is a New York-based freelance health and science journalist.