What are the main causes of gas?

Gas in your stomach is primarily caused by swallowing air when you eat or drink. Most stomach gas is released when you burp. Gas forms in your large intestine (colon) when bacteria ferment carbohydrates — fiber, some starches and some sugars — that aren't digested in your small intestine.

Excessive flatulence can be caused by swallowing more air than usual or eating food that's difficult to digest. It can also be related to an underlying health problem affecting the digestive system, such as recurring indigestion or irritable bowel syndrome (IBS).

Some flatulence is normal, but excessive farting is often a sign that the body is reacting strongly to certain foods. This can indicate a food intolerance or that a person has a digestive system disorder, such as irritable bowel syndrome. Typically, people pass gas 5–15 times per day.

While farting every day is normal, farting all the time is not. Excessive farting, also called flatulence, can make you feel uncomfortable and self-conscious. It might also be a sign of a health problem. You have excessive flatulence if you fart more than 20 times per day.

Some experts believe that as you get older, you fart more because your metabolism slows down. The food sits longer in your digestive system, creating more gas. Also, your stomach makes less of the acid needed to digest food well. What's more, your digestive system is made up of muscles.

People may experience gas at night due to eating close to bedtime. Specifically, lying down very soon after eating may cause indigestion, which can produce gas. Also, eating a large meal can trigger some conditions, such as irritable bowel syndrome (IBS).

Eat your last meal or snack a few hours before bed. Giving time between your final meal of the day and your sleep reduces the amount of gas your body produces when you sleep. Try alpha-galactosidase anti-gas pills (Beano and BeanAssist), which break down the carbohydrates in beans and other vegetables.