Your top 5 flatulence questions, answered

Gas and bloating in the intestinal tract is one of the most common problems we encounter in gastroenterology. Gas in the digestive tract comes from a variety of sources, such as aerophagia (excessive air swallowing), partially digested foods or intestinal bacteria.
Other causes include:

• Rapid eating, talking during meals, chewing gum or eating hard candies — air is also swallowed with saliva during these activities

• Sinus problems, post-nasal drip, mouth breathing and using a CPAP machine for sleep and breathing problems — air is blown into both the GI tract and the lungs

• Eating hard-to-digest foods, especially vegetables, such as cabbage, broccoli, cauliflower and onions

• Drinking fizzy or carbonated drinks

• Ingesting dairy products if you are lactose-intolerant

Gas can be trapped in the upper or lower intestinal tract. When it is in the upper tract, we burp more. In the lower tract, excessive flatus — or passing gas — results. It turns out that there are more nerve endings in the GI tract than there are anywhere else in the body, except the brain. The sensory neurons in the gut respond to gaseous distension of the gut to cause symptoms of abdominal discomfort, cramping, bloating or even severe pain. The discomfort triggers a response to release the gas.

It is perfectly OK to hold the gas in, but it may cause discomfort depending on your threshold of sensing pain. Gas will eventually be absorbed if you don’t let it out, but your body has to absorb it faster than the rate of acquiring gas to avoid discomfort, distension or the sensation of bloating. Once absorbed through the intestine, it enters the blood stream to be carried to the lungs and exhaled.

First, avoid the common causes of gas when possible. Patients with irritable bowel syndrome (IBS) can try a low-FODMAP diet (FODMAP stands for “fermentable oligosaccharide, disaccharide, monosaccharide and polyols”). This diet has a low content of gas-forming foods and can result in a tremendous reduction of gas in some people.

A lactose-free diet, gluten-free diet and certain forms of probiotics can also reduce intestinal gas distension. Patients should consider blood testing for celiac disease (an allergy to gluten, which is a protein found in wheat, rye and barley) prior to starting a gluten-free diet, as testing after starting the diet can make the results inaccurate. The probiotics typically replace the body’s natural bacteria population with bacteria that are less likely to cause gas or bloating.

Most people with isolated excessive gas or bloating do not necessarily need to see a gastroenterologist unless there are other associated symptoms, known as the “alarm symptoms.” These include excessive and unintentional weight loss, bleeding or anemia, or a family history of GI cancers. For the most part, the odor of gas does not suggest any particular health problems. The stench that often accompanies the passing of gas is simply a result of the process of bacteria breaking down certain foods and does not require medical attention, no matter how bad it may smell.