3 Reasons Why Your Stomach Is Sensitive to Carbonated Drinks

Fizzy beverages are satisfying to sip, but for those who are sensitive to carbonated drinks, it can cause more discomfort than it's worth. Indeed, sparkling beverages can cause digestive issues like stomach pain, bloating and gas.

First things first, what makes a drink carbonated? The added gas is what makes soda or sparkling water bubbly. "Carbonation, which adds a unique flavor and texture to beverages, is the process of trapping and dissolving the gas CO2 [carbon dioxide] in water," says Amanda Blake, RDN, a nutritionist with Pacific Nutrition Partners in Los Angeles.

But when you sip a fizzy beverage, the carbonation might have a negative effect on your stomach. So if you're sensitive to carbonated drinks, here are the reasons why that may be.

Think of swallowing a fizzy drink like swallowing a big gulp of only air — they're more similar than you might think.

"Swallowing a carbonated beverage introduces air into the stomach, similar to eating too fast or drinking too rapidly," says Blake. And this can translate to stomach pain after drinking carbonated beverages.

A small December 2018 study in the ‌Journal of Nutrition‌ tested the effects of carbonated beverages on 34 people and found that carbon dioxide increases what's known as gastric volume, which can lead to feelings of bloating, nausea or fullness. In other words, carbonated water (or other fizzy drinks) does bloat you.

What's more, "For some people, this can be extremely distressing and lead to discomfort," says William J. Bulsiewicz, MD, a gastroenterologist in Mount Pleasant, South Carolina, and author of the book ‌Fiber Fueled.‌

And it could take hours to pass the gas from carbonated water. "Flatulence usually occurs in less than 24 hours, but you will belch almost immediately after consuming carbonated water," he says.

But according to Blake, gas (in this case, carbonation) does help digestion, so for some people, there are no side effects of drinking carbonated beverages.

How does carbonated or sparkling water does help with digestion, exactly? It can ease constipation and improve swallowing, all of which supports healthy digestion, per UChicago Medicine. So if you're constipated, sparkling water helps with bloating by moving stool out of your body.

"Individuals may react differently to carbonation," Blake says. "Some may feel bloated and distended, others may not notice any difference or [may] release excess gas in the form of a harmless belch. Some may experience a feeling of fullness with a carbonated beverage, while it may drive the hunger of others."

Another small September 2016 study in ‌PLoS One‌ found that carbonated drinks like seltzers, sodas, beer and sparkling water make people feel as if they've had more to drink than they actually have, due in part to what's described as gastric filling — in this case, filling up the stomach with air from the bubbles.

The researchers also noted that pain receptors in the body may detect cold and carbonation and register them as pain.

Some carbonated beverages contain added sugars and caffeine, which adds to their potential negative health effects, Dr. Bulsiewicz says. "Some people with [irritable bowel syndrome (IBS)] will have aggravation of their condition if they consume caffeine, and it will give them diarrhea," he says. This can also be especially irritating if you drink the carbonated beverage during exercise.

Sugary sodas are not only carbonated, they're also loaded with empty calories, which can contribute to obesity and its related health risks. In fact, sugar-sweetened sodas are the number one source of added sugar in people's diets, according to the American Heart Association, which is why sugary carbonated drinks aren't the best choice when it comes to weight loss.

Plus, "if you overdo it on sugar, you are going to get diarrhea," Dr. Bulsiewicz says.

Diet sodas contain artificial sweeteners, which is why they are so low in calories. "Artificial sweeteners can cause a laxative effect," he says. "They pull water into your colon and help to mobilize stool, which can lead to the runs." This is especially true of the artificial sweetener sorbitol.

So if you're sensitive to carbonated drinks that also contain any of these ingredients, it might be best to stick to options with natural flavorings or no additives at all.

Although studies have not linked carbonated beverages to chronic health issues like IBS or gastroesophageal reflux disease (GERD), those living with these and other conditions may find that drinking too much sparkling water makes their symptoms worse and causes more pain.

"It won't cause IBS," Dr. Bulsiewicz says‌.‌ "But if you are someone who is sensitive to carbonated beverages and you have IBS, the bloating and gas may cause a flare."

"The acidity level and carbonation may aggravate [GERD] symptoms for some," says Cassie Berger, RDN, who is also a nutritionist with Pacific Nutrition Partners. "It's best for individuals to assess their own tolerance levels and modify intake if needed." She recommends diluting a fizzy drink with juice or coconut water to lessen the nausea effect.

"The bottom line," Blake says, "is avoid carbonation if it causes you discomfort."