One of my favorite hobbies is searching PubMed.gov. I love PubMed — I use it to develop stories, to find sources, and to generally learn about the world around me. For instance: farting.

There was a superstar of the fart literature A PubMed search returns 14 results with "excessive flatulence" in the headline and abstract. A lot of these are about treating constipation, which is admittedly no fun. But there are some standouts, like this gem from 1975: "As yet," writes MD Levitt, "there are no data available that prove excessive flatulence is actually caused by the presence of excessive intestinal gas." Blow my mind, why don't you? As of 1975, there was no proof that farting was caused by too much intestinal gas? I gotta see more work by this Levitt character. As it turned out, he was the superstar of the fart literature.

Sure, enough, also in 1975, Levitt published another paper, this time in The New England Journal of Medicine, where he pumped people full of argon. See, these 18 patients had a lot of GI symptoms — gas, bloating, and flatulence. But they had a normal volume of gas in their guts, which had normal composition. Perhaps, though, the scientists reasoned, they reacted badly to any excess gas! And that is how 18 people wound up getting argon pumped into their butts. (Argon was chosen because it wouldn't react to their own intestinal gasses, I guess??????) The gas that they then ejected was "quantitatively collected in a series of 100-ml syringes and analyzed by gas chromatography." Can you even imagine. Haha, like:

Within 15 to 20 minutes of the start of the infusion, control subjects passed gas per rectum at a rate approximating the infusion rate, and they usually experienced very little associated discomfort. In contrast 13 of the 18 patients experienced severe discomfort during the infusion of the gas, and in six subjects the pain was of such intensity that the infusion had to be discontinued. This enhanced pain response was associated with abnormalities in the transport of gas through the gut, with a tendency to pass gas less rapidly per rectum and for increased quantities of the infusate to reflux from the intestine back into the stomach.

This is so funny to me! They farted at about the same rate you filled them up with gas, who would have guessed! No less surprising, it hurts to have gas pumped up your tuckus: fully a third of patients had to stop because the pain was so bad. Anyway, this improbable study found that the feeling of being bloated or gassy wasn't necessarily correlated to the amount of gas in one's gut.

These results therefore provide numerical support for the personal experience of Dr. Walter Alvarez, who reported that "when I thought I was full of gas there was no sign of it in the bowel, and when I was comfortable the roentgenograms sometimes showed the splenic flexure to be markedly distended." Similarly, in a series of over 400 routine abdominal roentgenograms in healthy persons, large accumulations of gas were not accompanied by feelings of abdominal distress. Thus, it appears that a subject is a poor judge of the volume of gas present in his intestinal tract.

This is a legitimate matter of scientific inquiry, and it looks like we're not very good at figuring out how much gas we're carrying! Anyway, given the differences between the group who experienced discomfort and the group who did not, the problem was not the gas itself, but how easily it moved through the gut.

Also: beans' bad reputation may be undeserved! Levitt pops back up in 1998 — hello! — on a case report for an "extremely flatulent patient." The good fart doctor determined that the patient was swallowing too much air, which was why there was so much farting. He, with colleagues, then recommended diagnostics for other doctors who might find themselves attempting to determine whether the cause of farting was coming from swallowing too much air or from production in the gut. Turns out that the gas composition will tell you the gas's source: too much nitrogen means you're swallowing air, while carbon dioxide, methane, and hydrogen tend to be found with gut-produced gas.

The other study worth noting found that beans' bad reputation may be undeserved: fewer than half of people noticed an increase in flatulence from eating pinto or baked beans; only 19 percent had more gas with black-eyed peas. Amusingly, people on control diets also reported a 3 percent to 11 percent increase in farting. "People's concerns about excessive flatulence from eating beans may be exaggerated," the authors write helpfully. "It is important to recognize there is individual variation in response to different bean types."

So true. So true.