4 Ways to Get Rid of Gas

Why do we pass gas, and what can we do about it?

Rob Lamberts, MD
7-minute read
Episode #70

How Often Do People Fart?

The average person passes between 500 and 1500 ml of gas from their rectum each day.  That translates to 1/2 quart to nearly 1/2 gallon of gas each day.  Most of this passes innocently and without notice of even the guilty party.  Some people seem to pass more than others (and some are proud of that fact).  Certain foods and medical conditions can alter this volume significantly.  I knew a guy in college, who...never mind.

What Causes Gas?

The composition of flatus is not too far from that of the outside world: it is mainly nitrogen, oxygen, hydrogen, and carbon dioxide.  Methane gas, a byproduct of the digestion of food, is also present in small quantities.  So where do all of these gasses come from?  The majority of intestinal gas is swallowed by the individual.  Eating, chewing gum, and smoking are all things that increase the swallowing of air.  Some folks swallow air when they are anxious, which of course results in increased output of gas, which could lead to social isolation and, of course, anxiety.

Why Does Gas Smell?

Gas is also produced by the creative genius of the bacteria in the large intestine, who take food we eat and turn it into methane and the more odoriferous substances for which flatus is notorious. If flatus was just expelling of these gasses, nobody would be too interested in this subject.  The real problem comes with some of the other gasses present in very small qualities.  These gasses are made up of compounds containing sulfur, which when combined with hydrogen creates hydrogen sulfide, the substance that produces the “rotten egg” odor. 

The bacteria get their raw material—that leads to the less than pleasant smell--through changes in the environment of the colon. Any of the following can be responsible for smelly gas:

Changes in how fast things move through the intestines--diarrhea or constipation can either let things hang out in the colon too long, or let food get into the colon before it’s digested.

Changes in the population of bacteria of the colon, through use of antibiotics.

Malabsorption conditions, such as lactose intolerance, ingestion of too much sorbitol (a substance that is in sugarless candy), and certain infections.

Increased intake of soluble fiber and complex sugars (the Nutrition Diva did a good episode on gas-causing foods).

Certain foods (like pork) have a huge effect on the aroma even though they don’t increase the amount of gas produced.


Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice, and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health related questions and issues.