Natalie Egan, MS, RD, LDN
Brigham and Women's Hospital
Previously published on Intelihealth.com
We all have gas. Yet, we're embarrassed to mention it to health-care providers and friends in social conversation. Ten percent to 20 percent of adults have the digestive complaints of belching or flatulence. Here's the good news: bloating or gas doesn't necessarily mean there is something wrong with digestion. But to minimize gas and its embarrassment, the first areas to focus on are diet and eating habits.
The three most common ways of expelling gas are burping, abdominal bloating, and flatus. Swallowed air, which may stay in the stomach for a period of time, is released by belching. Bloating typically occurs with air that is trapped in the colon or small bowel. Air passed through the bowel is typically passed as flatus. A normal individual emits flatus from 12 to 25 times per day, with more gas in the intestine later in the day than earlier.
Intestinal gas is made up of oxygen, nitrogen, carbon dioxide, hydrogen and methane. The composition varies depending on the type of intestinal gas. Gas is caused by various factors, the most common of which are eating behaviors and the bacterial fermentation of certain foods.
The colon is filled with bacteria, yeasts and fungi, which break down the foods not digested by the small intestine, mostly different forms of carbohydrates. These bacteria particularly enjoy undigested carbohydrates, and the fermentation leads to gas production, hydrogen and methane expelled as flatus. Lactose is one of the most common sources of gas-causing carbohydrate, affecting people who are "lactose intolerant," meaning they do not have the enzyme lactase needed to digest the carbohydrate. Typically, lactose is found in dairy products. Beans are the second most common carbohydrate implicated in gas production. The indigestible carbohydrate in beans that typically causes flatus is raffinose.
Eating behaviors and other habits such as gum chewing, gulping foods and drinking with eating can cause us to swallow air. Bulky foods such as lettuce, cabbage, and dense breads not chewed into small enough pieces increase swallowed air.
Typically, swallowed air contains oxygen, nitrogen and carbon dioxide. It tends to not have a foul smell, but it does contribute to the discomfort associated with gas.
People vary widely in how sensitive they are to gas production. Keeping a food record to document incidences of gas in relation to foods eaten can shed light on whether food or behavior may be aggravating the situation.
Bloating is a sensation that makes the abdomen feel larger than normal. The abdomen doesn't get physically bigger until its volume increases by one quart, so the bloated feeling may occur, but the abdomen is not distended. Intestinal gas may cause the feeling of bloating.
Here are additional suggestions to decrease bloating:
It is important not to completely omit foods from the diet that may cause gas. As we know, a high-fiber diet is important for bowel regularity and colon health, so it is well worth the patience it may take to slowly build up tolerance to these types of carbohydrates. Start by adding the offending high-fiber food in smaller quantities, such as a half cup or less. Be sure that fluid intake and activity levels are adequate, as they help to move foods through the digestive tract.
Many advertisements tout medications or remedies that reduce gas and bloating. Some have been shown to be of value in clinical studies, others have not yet been proven scientifically but are anecdotally helpful. Before trying anything, you may want to consult with your physician.
Two products on the market can help with food-related gas and bloating. Both products are packaged forms of the enzymes needed to break down the problematic carbohydrates. Lactase, found in products such as Dairy Ease and Lactaid, can be taken with dairy foods to help break down lactose and lessen gas. Beano helps digest the indigestible carbohydrate in beans and other gas-producing vegetables.
Natural remedies for gas include:
Over-the-counter gas remedies include:
In most situations, occasional gas and abdominal discomfort does not require medical attention. Over- the-counter products, or a self-assessment of habits and changes in eating behaviors can help remedy the situation. However, you should seek medical attention when there is an increase in frequency, location or severity of the symptoms, or if they are accompanied by weight loss, diarrhea, vomiting or heartburn.
For over a century, a leader in patient care, medical education and research, with expertise in virtually every specialty of medicine and surgery.