Passengers often experience an increase in flatulence during flights, a phenomenon known as high-altitude flatus expulsion (HAFE). This occurs because the ambient pressure in an aircraft cabin decreases as the plane ascends, causing gases in the human gut to expand. According to Boyle’s gas law, gases expand in volume as pressure drops; in a cabin environment, intestinal gases can expand by approximately 30% in volume.
Why do I have to fart so much on planes?
Beyond the expansion of existing gas, researchers have identified other biological processes. A study published in the New Zealand Medical Journal suggests that the rapid increase in altitude draws carbon dioxide from the bloodstream into the bowels. This process increases the total volume of gas in the intestines, leading to more frequent passing of gas.
Intestinal gas typically consists of nitrogen, carbon dioxide, and hydrogen, along with smaller amounts of methane, oxygen, and sulfur. When these gases expand or increase in volume, the body naturally seeks to release them to relieve pressure. This is similar to how gas behaves in liquid containers under pressure, where changes in pressure changes the behavior of the same volume of gas.
How to prevent gas when flying
To reduce the production of gas in the gut before and during a flight, passengers can follow these dietary and medical recommendations:
- Avoid carbonated drinks: These introduce extra gas into the digestive system.
- Limit high FODMAP foods: These are short-chain carbohydrates that the small intestine struggles to break down, which then ferment in the large intestine. Common examples include lactose, legumes, garlic, onions, honey, and wheat.
- Use over-the-counter medication: Simethicone (often sold as Gas-X) can break up large gas bubbles, making them easier to pass and reducing the feeling of pressure.
- Stay active: Standing and moving around the cabin can prevent gas from becoming trapped.
Is it OK to fart on a plane?
While passing gas is a natural bodily function, holding it in can lead to uncomfortable pressure and bloating. In severe cases, trapped gas can cause upper respiratory issues, including pain or sinus bleeding. More critically, expanded gas that escapes the intestines into the abdominal cavity can interfere with medical devices like insulin pumps. Understanding the importance of your appendix and the overall function of the gut microbiome helps illustrate how the body handles waste and gas production.
While some passengers may feel embarrassed, the biological reality of HAFE is a constant factor for many. Just as a dog can sense if someone dislikes you, passengers in close quarters can certainly notice the same biological signals of digestion. However, the physiological response to pressure changes is an unavoidable biological fact of high-altitude travel.
