Here's What Happens When You Hold Back Gas

A taxi sticker that bans farting.
As this taxi sticker suggests, we live in an increasingly fart-retentive world. Zoenie/Shutterstock

There's nothing like a gastro-nuclear explosion to ruin dinner. Or a date. Or even a job interview.

But we don't get much warning when our bowels decide it's time to discharge a little gas.

In fact, we may feel a sudden pressure, followed by a deep internal rumble. Something wicked this way comes.

The thing is, everyone's got to unleash that inner beast. In fact, the average human — men and women equally — contributes around 15 farts per day to the Earth's atmosphere.

(Some people, like your Uncle Hank or this guy in the elevator, can wildly exceed that quota.)

Man stands in an elevator after farting.
No matter how hard we struggle to hold back gas, it will find a way out. Diane Diederich/Shutterstock

Now, just imagine how that Santa Claus at the local mall must feel. There's no way his boss is giving him 15 to 20 breaks per day. And yet, he holds strong. Think of the children!

But just one sudden movement — a nervous giggle, perhaps — and the floodgates open.

Hello, Stinky Santa.

The thing is, Santa isn't doing his body any favors by keeping all that gas bottled up tight. In fact, there's a lot that goes wrong when we deny our stomach a chance to vent.

But to understand the perils of fart-retention, one must first understand how flatulence works.

The science of gas

Cute, smiling healthy stomach and bowel, intestine character
Research suggests we unleash about 15 farts per day — and it's usually perfectly healthy. Sabelskaya/Shutterstock

Intestinal gases are a natural byproduct of digestive and metabolic processes. Even that sandwich you just had for lunch is probably being stripped down for nutrients, a biochemical conveyor belt that results in the creation of several gassy emissions.

About 60 percent of those gases are nitrogen, with 20 percent being hydrogen. Carbon dioxide, methane and oxygen are also present. But the real stink factor is the tiny bit — about 1 percent — of sulfur.

That's what gives a fart its elevator-clearing stench.

At the end of the gas-creation line is tidy little apparatus whose name you don't often see in print: the anus.

From there, those pent-up gases blossom into the local atmosphere. A fart is born.

Now, what happens if it happens to be a really no-good-terrible-please-god-no time to bring such a thing into the world?

You shall not pass!

But at what cost?

Never mind the major discomfort of trying to contain a gastro-tsunami. It can lead to a permanently distended belly.

And, as Claire Collins, a professor in nutrition at the University of Newcastle, writes in The Conversation, that pent-up gas will always find a way out.

Some gas, Collins notes, will be reabsorbed into our circulatory system and get exhaled in your breath. (Date killer, indeed.)

Even scarier? The internal reactor may build up so much pressure, all the squirming and puckering in the world won't be able to hold it back.

Those angry gases will blast through the back door, roaring vengeance and visiting hell on anyone who tries to hold them back. Even your date at the opera.

It probably wasn't quite like this in the old days. Ancient humans likely expressed their bowels freely and even with some pride. There may have even been an element of musical artistry to the passing of gas.

But an underrated hallmark of a civilized society is knowing when to clench our butts, and knowing when to just let go.