Last month we discussed the very common condition of GERD/acid reflux, this month we are going to continue along those lines and talk about gas in the digestive tract. I commonly have patients who are professional drivers tell me that when they are on the road they seem to produce more gas than when they are at home.

By the end of this article, you will understand why this is! Everyone has gas and eliminates it by burping or passing it through the rectum.

However, many people think they have too much gas when in fact they have normal amounts. Most people produce about 0.5L to 2L per day and pass gas about 14 to 20 times. The gas produced in our digestive tract mainly consists of odourless vapors such as carbon dioxide, oxygen, nitrogen, hydrogen, and sometimes methane. The unpleasant odour of flatulence comes from bacteria in the large intestine that releases small amounts of gases that contain sulfur. Although gas may be uncomfortable and embarrassing, it is not a life-threatening condition.

Understanding its causes and treatments will help most people find some relief.

The first thing I want to discuss are the causes of gas. Gas in the digestive tract come from two sources; swallowed air and normal breakdown of certain undigested foods by harmless bacteria, naturally present in the large intestine (colon).

Air swallowing is a common cause of gas in the stomach. Every one of us swallows small amounts of air when we eat or drink. However, eating or drinking rapidly, chewing gum, smoking or wearing loose dentures can cause some people to take in more air. Burping or belching is the way most air leaves the stomach. The remaining gas moves into the small intestine, where it is partially absorbed. A small amount travels into the large intestine for release through the rectum.

The body does not digest and absorb some carbohydrates in the small intestine because of a shortage or absence of enzymes. This undigested food then passes from the small intestine into the large intestine, where normal, harmless bacteria breaks down the food, therefore producing hydrogen, carbon dioxide, and, in about one-third of all people methane.

Eventually, these gases exit through the rectum. People who make methane do not necessarily pass more gas or have unique symptoms. However, a person who produces methane will have stools that consistently float in water. Research has not shown why some people produce methane and others do not. Foods that produce gas in one person may not cause gas in another. Some common bacteria in the large intestine can destroy the hydrogen that other bacteria produce. The balance of the two types of bacteria may explain why some people have more gas than others.

Now that we know the basics about the causes of gas, let’s discuss the specific types of foods that increase the production of gas. The first thing to keep in mind is foods that contain carbohydrates cause the production of gas.

Conversely, fats and proteins cause little gas. We all know that beans cause gas, but why?

Beans contain the complex sugar raffinose. During the digestion of raffinose the intestine produces gas as a byproduct. Another sugar is lactose, which is the natural sugar found in milk and milk products, such as cheese and ice cream, as well as processed foods like bread and cereal and salad dressing. Many people have low levels of the enzyme lactase which is needed to digest lactose after childhood. As people age, their enzyme levels decrease. As a result, over time people may experience increasing amounts of gas after eating foods containing lactose.

Other sugars found naturally in fruits including apples, pears, peaches and prunes, as well as in artificial sweeteners in many low calorie foods and sugar-free candies and gums can lead to an increase in gas production. Finally, many foods contain soluble and insoluble fiber. Soluble fiber dissolve easily in water and takes on a soft, gel-like texture in the intestines. Found in oat bran, beans, peas, and most fruits, soluble fiber is not broken down until it reaches the large intestine, where digestion causes gas. Insoluble fiber, on the other hand, passes essentially unchanged through the intestines and produces little gas.

The most common symptoms of gas are flatulence, abdominal bloating, abdominal pain and belching. However, not everyone experiences these symptoms. Belching is the most common form of gas release. An occasional belch during or after meals is normal and releases gas when the stomach is full of food. However, people who belch frequently may be swallowing too much air and releasing it before the air enters the stomach. In some cases, people with chronic belching may have an upper GI disorder, such as a peptic ulcer disease, gastroesophageal reflux disease (GERD), or gastroparesis. Another common complaint is the passage of gas through the rectum (flatulence). However, as stated above, it is normal to pass gas up to 20 times a day. If you truly are passing too much gas, it may be due to the malabsorbtion of carbohydrates.

Abdominal bloating and pain are far less common and may be a result of an underlying condition causing an intestinal disorder.

Thus, if you do experience these symptoms regularly it is best to check with your doctor.

Finally, let’s talk about how excessive gas is treated. In most cases, this condition can be greatly reduced by diet modification. Limiting foods that cause gas from one’s diet is the first line of defense. If this fails, your doctor may suggest taking over-the-counter medicines such as antacids and digestive enzymes. If this too fails, your doctor may prescribe medication to help reduce your symptoms, especially if there is an underlying intestinal condition.

– Dr. Christopher Singh runs Trans Canada Chiropractic at 230 Truck Stop in Woodstock, Ont. He can be reached at 888-252-7327, or email TCC@transcanadachiropractic.com