Farting or flatulence (known also by its many slang, such as cutting the cheese, passing gas, and breaking wind) is a very common occurrence. We all product fart (or formally, flatus) as a result of our natural digestive process. The passing of too much gas, however, can become a discomfort and is considered a social bane.

A person’s ability to control their farting is dependant on muscles that are part of the walls of the anus and the muscles on the outside of the anal canal. These muscles are known respectively as the internal anal sphincter and the external sphincters. These muscles allow a person to control or forcefully expel the gas. When these muscles do not work well or are not in sync with each other a person suffers from uncontrollable flatulence.

There are essentially five odorless gases that make up a fart:

• Oxygen and Nitrogen
  The oxygen and nitrogen in a fart both come from the air that we swallow. Some of this swallowed air is absorbed into our body, but the part not absorbed comes out as passed gas.
  
  
• Carbon dioxide (CO2)
  The acid in our stomachs churning during the digestion of food along with bacteria in the colon working on unabsorbed sugar creates carbon dioxide.
  
  
• Hydrogen
  The hydrogen in a fart is also due to the colon bacteria working on unabsorbed sugars.
  
  
• Methane
  Methane is a gas that only some of us incorporate into our farts. The production of methane is actually not at all related to the types of food we eat. Only 30% of people actually produce methane.

Primary Reason for Farts: Too much sugar

Complex sugars such a sucrose (table sugar) and lactose (milk sugar) are difficult for the body to absorb and can lead to the production of gas. Complex sugars are essentially simple sugars (like glucose, fructose, and galactose) that are bound by chemical linkages. While simple sugars are easily absorbed by the small intestines, complex sugars are harder for the body to breakdown. Normally these complex sugars end up in the large intestine where bacteria tries to break them down and hydrogen and carbon dioxide are formed.

Lots of different types of foods contain complex sugars. Beans, for example contain a complex sugar called raffinose that is not easily broken down in the small intestine. Other examples of gas producing foods are:

• Fruits, such as apples, bananas, figs, grapes, prunes, and raisins
• Beans or legumes
• Bran-rich food, such as bread and whole-grains
• Certain vegetables, such as cabbage
• Dairy products
• Pastry

Breads can produce gas because they contain sugars and gluten. Gluten is a protein that actually slows down the time it takes to break down both simple and complex sugars. This means that the sugars end up getting broken down instead by bacteria which causes the production of gas.

Why does a fart smell?

The five different gas listed above are actually do not contribute to fart's odor problem. The terrible smell is produced by trace amounts of hydrogen sulfide, ammonia, mercaptan, indole, and skatole. These are all things that are produced during the digestion process.

Prevention

If you are concerned with the amount of gas you are passing there are some things that you can do:

• Don’t swallow so much air. Avoid talking and eating at the same time, gum chewing or other activities that encourage the swallowing of air.
  
  
• Treat existing digestive problems, such as irritable bowel syndrome, as these may reduce the body's ability to digest complex sugars.
  
  
• Try to eliminate gas producing foods from your diet. This means cutting down on complex sugars or gluten rich foods.
  
  
• If you cook a lot of beans, try soaking them overnight, then discarding the soaking water and cooking using fresh water. This helps dilute and eliminate the complex sugars in beans.
  
  
• Avoid artificial sweeteners
  
  
• Take lactase, an enzyme that break down lactose sugar to forms that are easier to digest; and alpha-galactosidase that breakdown complex sugars in beans and cabbage. These enzymes are available as popular over-the-counter products, such as Lactaid and Beano.