Common questions about bloating and gas

I hear concerns about gas and bloating all the time from patients. What may freak you out is that the average adult produces about one to three pints of gas each day, which is passed from below 14 to 23 times per day. Burping before or after a meal is also normal. So how much is too much, and why does it happen?

1. Where does the gas come from? There are two sources of intestinal gas: gas that is ingested (swallowed air) and gas produced by bacteria in the colon.

2. Burping vs. passing gas: Most swallowed air is eliminated by burping, which means that only a small amount of air passes from the stomach into the small intestine. When sitting up, most swallowed air passes back up the esophagus and out of the mouth, which will cause you to burp. When lying down, swallowed air tends to pass into the small intestine, which can cause you to pass gas.

3. Burping foods: Burping is more common with foods that relax the sphincter at the lower end of the esophagus where it joins the stomach. Peppermint, chocolate, and high fat foods will do this.

4. Passing gas: The colon contains billions of harmless bacteria. The stomach isn’t great at digesting certain carbs, so the bacteria in the colon have to do the work. Those foods will cause you to have more gas because the colon bacteria are working hard.

5. Why do farts smell? Though a minor component of gas, trace amounts of sulfur cause the smell.

6. Why do I get gas and bloating with dairy? Some people are not able to digest certain carbohydrates. A classic example is lactose, the major sugar in dairy products. Eating dairy (lactose) may lead to increased gas production, along with cramping and diarrhea.

7. What about bacterial overgrowth? For reasons we aren’t sure about, some people tend to harbor large numbers of bacteria in their small bowel and are prone to develop excessive gas.

8. Why do I burp more than other people? Pay attention to causes of increased swallowing, such as chewing gum and smoking. Eat slowly without gulping and avoid carbonated beverages.

9. What over-the-counter meds help for gas and bloating? Products that contain simethicone (Maalox, Mylanta, and Gas-X) help for gas and bloating. Also try Pepto-Bismol to reduce the odor of unpleasant-smelling gas.

Medically reviewed in January 2019.