Do the math and that’s a lot of gas inside the cabin.
“Even on the ground, we all pass a surprising quantity of gas every day. According to one estimate, the average person breaks wind 10 times every 24 hours, expelling about 1 liter in total. The gases are brewed from food that has failed to be absorbed by the gut, and so is fermented by bacteria, which produce nitrogen, carbon dioxide, and hydrogen – along with more odorous, sulphurous compounds.
But if our flatulence on ground level passes mostly unnoticed (or is at least politely ignored) in day-to-day life, it can become something of an unwanted companion in the confines of an air cabin. Its frequency on planes is simple physics, Rosenberg says. “The pressure drops and the air must expand into more space.” That 1 liter of gas now needs to fill a 30% bigger volume, leading to that nasty bloating feeling. This seems to be a regular problem for pilots – more than 60% report feeling regular abdominal bloating, much higher than the average for office workers.”
There’s not a lot you can do about it according to the article but definitely watch what you’re eating inflight. Opting for the vegan option will help those who are lactose intolerant or you can try some flatulence filtering underwear.