As humans, we don’t produce gas on our own. So when we have gas and bloating it is due to two main causes — either swallowed air or gas produced by bacteria.
We all swallow certain amounts of air throughout the day. This commonly happens during eating and drinking, especially if we eat very fast. It’s also more common in people who chew gum, smoke and drink carbonated beverages. Typically we don’t swallow enough air to be problematic, but some people do, and what they develop is gas and bloating.
Gas Production by Bacteria
This is a much more complex topic than swallowing air. We have literally trillions of bacteria that live in our gastrointestinal tract. They don’t cause us harm and, in fact, without
One of the biggest factors in how much gas is produced in our bowels is what we put into them. Bacteria love to ferment carbohydrates like pasta,
- Fructose (fruits, high-fructose corn syrup)
- Lactose (dairy)
- Fructans (wheat, onions)
- Polyols (sweeteners, sorbitol, stone fruits like avocado, cherries,
Another topic I focus on when investigating the cause of gas and bloating is medication. Not just prescription medications, but also over-the-counter ones, including supplements. Some medications cause gas because they contain fermentable products, such as lactose or gluten. Some medications affect gas production because they alter our normal bowel bacteria. When we take things like acid blockers (for heartburn) or antibiotics (for infections), they temporarily affect the bacteria in our bowels and can alter the way they ferment foods.
There are certain health problems that can predispose us to more gas and
Diabetes is a common one. It affects both the motility of our bowels and affects our immune system.
Prior surgery on our bowels will affect motility.
Celiac disease is a condition in which you have
Dietary intolerances, such as lactose intolerance or fructose malabsorption, may cause gas and
Irritable bowel syndrome (IBS) may cause gas and
Inflammatory bowel disease, like ulcerative colitis or Crohn’s, may cause gas and
Intestinal blockage, heart disease, gallstones and appendicitis can also cause symptoms similar to gas and
It’s easier to prevent gas and bloating than it is to treat it, so this is always my focus with patients. If we think swallowed air is part of the problem, we work on eating slower and trying not to talk while eating. We also minimize carbonated drinks, chewing gum and cigarettes.
Next, we focus on dietary changes. I start them on a low-carbohydrate diet (which is good for overall health and weight as well), and we focus on reducing the FODMAP foods. We minimize unnecessary medications and over-the-counter supplements and optimize treatment of underlying medical conditions.
These types of changes are hard, especially when we are changing lifelong habits, but they work. When prevention doesn’t work, we focus on diagnosing an underlying cause and treating it.
- Evidence Based Dietary Management of Functional Gastrointestinal Symptoms: The FODMAP Approach
- The Normal Bacterial Flora of Humans
- Intestinal Gas Dynamics: Mechanisms and Clinical Relevance
- The Effects of Methane and Hydrogen Gases Produced by Enteric Bacteria on Ileal Motility and Colonic Transit Time
- Methane, a gas produced by enteric bacteria, slows intestinal transit and augments small intestinal contractile activity
- Small Intestinal Bacterial Overgrowth (SIBO) in IBS