After a certain amount of time, things are going to get UGLY.

Just like the famous book says, everyone poops. But let’s be real, going at the office or at bae’s can be super awkward, prompting many of us to develop some odd holding patterns.

But holding in your poop when you gotta go is not only uncomfortable, it can also be unhealthy. “The idea of holding it isn’t the best thing,” says Niket Sonpal, M.D., assistant clinical professor at Tuoro College of Osteopathic Medicine in New York.

He gave us the scoop on poop, and what happens in your bod when you try to hold it in.

When you gotta go…

“When stool hits parts of the rectum, it sends you the signal saying ‘hey man, you’ve got to find a place to got to the bathroom and unload,’” says Sonpal.

While everyone’s schedule and frequency is different, it usually happens right after you eat or have your morning cup of coffee—caffeine can act as an intestinal stimulant making you run for the porcelain throne after downing your cappuccino.

After two hours…

“Its really hard to hold your poop in. You have to tighten the voluntary sphincters,” says Sonpal.

“In the first few hours, you’ll feel a sense of abdominal pressure. Some people describe it as abdominal cramping, whereas some people have more urgency.”

In other words, holding it is a fast track to that gassy, bloated feeling you can’t seem to shake.

Learn more fascinating facts about the female anatomy:

After six hours…

“Your body will eventually start to impact your poop,” says Sonpal. Not good.

He adds that at this point, you might actually loose the urgency to go, but that’s not because your poop has magically disappeared—instead, you’re just becoming constipated.

After 12 hours…

“The longer the stool stays in the harder it gets,” says Sonpal.

At this point, you may actually start to notice a distended belly—the pressure builds until you can’t hold your stomach flat even if you try.

As the stool gets harder in your colon, you up your risk for an uncomfortable trip to the bathroom, says Sonpal. You may experience straining, bleeding, and even small tears.

If you keep holding it…

“I’ve never heard of anyone dying from holding poop, but in adults, voluntarily holding it in is just going lead to impaction where the stool is rock hard,” Sonpal says. If it gets impacted enough, you might need laxatives or even manual removal to get it out. Yikes.

The bottom line? “Go to the bathroom when your body is telling you,” Sonpal says.

If you can’t get to a bathroom right away, definitely make it a priority in the first few hours.