Health

Do men or women have worse farts? Science has the answer.

Added bonus: Here’s why air travel tends to make people gassy.

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By Trisha Pasricha, MD, Washington Post

updated on April 6, 2026 | 10:11 AM

4 minutes to read

The following is an excerpt from “You’ve Been Pooping All Wrong,” by Trisha Pasricha, MD, MPH, which will be published on Tuesday.

Science has finally settled the age-old debate of whose farts smell worse – men or women. But to appreciate the answer, you need to understand how researchers figured it out. The methodology alone deserves an award.

The man responsible is Dr. Michael Levitt, a gastroenterologist who joined the Minneapolis Veterans Affairs hospital in 1978. An Air Force veteran himself, he would become known as the “King of Farts” to his colleagues for his interest – and eventually unparalleled expertise – in one very particular subject: the status of flatus.

Levitt didn’t ask for this honor. It was a life that was chosen for him. One day, while still a gastroenterology fellow, he was called into his adviser’s office and introduced to a new laboratory instrument: the gas chromatograph. The tool could be used for many applications – to analyze gas content in soil or even in crime scene investigations – but to these two gastroenterologists, it was clear that someone should use it to better understand the most pressing of scientific needs: farting.

And so, an illustrious career was born. Levitt eventually published over three hundred original scientific works, was honored with a Distinguished Achievement Award by the American Gastroenterological Association, and even consulted for NASA – developing spacesuits filtered with activated charcoal to prevent astronauts from having to inhale their own flatus during a spacewalk.

But it was one particular study that put the gender debate to rest – and it is a study I return to often, both in my clinic and at dinner parties where I have, on occasion, misjudged the room.

Levitt invited sixteen healthy men and women to consume items that boost gas production – pinto beans and a synthetic sugar called lactulose. Participants then showed up to the laboratory, where a rectal tube was inserted and made a gas-tight seal with their derrieres. The tube was connected to a gas-impermeable bag and, after farting, its contents were subsequently evaluated by chromatography.

It gets better.

The flatus collected in these bags was then sniffed and rated by two independent judges on a linear scale where zero was “no odor” and 8 was “very offensive.”

Don’t you love gastroenterology?

In 2003, Popular Science magazine ranked Levitt’s “flatus odor judge” as the worst job in science. But their contributions were enormous. They found that, compared to that of men, the flatus of women had a much greater odor intensity.

Now hold your horses.

The study also found that men produced a larger volume of gas per toot – roughly half a cup’s worth at a time. And Levitt argued that because flatus’s ability to stimulate the nose is more dependent on volume than on concentration of noxious gas, these differences between the sexes balanced out in real life.

It was, in other words, a tie.

Still not buying it? Other perceived differences may be because more women have better perfected the slow and steady release of flatus that effectively dampens the sound – which some men, particularly in their teenage years, choose not to exercise.

Still, in certain situations, no matter your skills in this regard, we are all helpless. One such situation is air travel. We are all gassy on a plane. Sometimes it’s you. Sometimes it’s your neighbor. Before you judge anyone aboard, remember the ideal gas law: PV=nRT.

With increasing altitude, air pressure – including intestinal air pressure – falls. Therefore, the volume of your intestinal gas has to expand. The air in your colon is blocked from traveling backward by a small muscular valve connecting it to the small intestine. Therefore the only path flatus can take is forward and outward, where it joins the recirculating cabin air for the remainder of the flight, giving “jet propulsion” a new meaning.

But outside of airplanes, we tend to have more power in mitigating the damaging effects of our gas upon friend and foe. If you need a simple last-minute solution: take bismuth subsalicylate over the counter. There is some concern about salicylate toxicity long-term, but for a critical moment – a special date, a work conference, a long flight – 524 mg by mouth four times a day beforehand will do the job. Bismuth subsalicylate – better known as Pepto-Bismol – binds and neutralizes more than 95 percent of sulfide gases in the gut. Another landmark discovery from the laboratory of Dr. Levitt.

You might say there are no winners here – only losers. Which is perhaps the most democratizing findings medicine has ever produced, and almost certainly among the few findings in the history of research produced by members of the American Gastroenterological Association that has ever settled a domestic dispute.

From “You’ve Been Pooping All Wrong,” by Trisha Pasricha, MD, MPH, to be published Tuesday by Avery, an imprint of Penguin Publishing Group, a division of Penguin Random House. Copyright © 2026 by Trisha Pasricha LLC.