What is happening when someone feels bloated?

Let’s start with some definitions. Gas is the volume of air and fermentation byproducts in your intestines. Distension is the visible, measurable swelling of your belly. Bloating is the sensation: pressure, tightness, fullness. They overlap and seem similar, but they are not the same thing.

Think of it like a smoke detector. Sometimes there is a fire. Sometimes you made toast. And sometimes the detector is set so sensitively that it shrieks at shower steam.

We tend to think of it like a balloon. When we feel bloated, clearly it must be because the balloon is getting pumped full of gas, getting stretched, and close to bursting. So this part may surprise you, but many people with daily bloating carry no more gas than anyone else. What’s different is how their gut interprets the gas they do have. For many people, it’s a disorder of the brain-gut axis.

Believe it or not, your belly can look distended and pregnant because of how your muscles respond, not necessarily how much gas is in there. Crazy, right?

The four causes of bloating

I’m going to take you into my head and show you how I think about bloating as a gastroenterologist. Again, it’s not just one thing, so you have to be prepared for all of the possibilities. I always think of four root causes for bloating, each living in a particular part of your gut. The location determines what will help.

Cause 1: Swallowed air.

Straws, carbonated drinks, gum, eating fast or stressed, mouth breathing, reflux. You’re not just swallowing food or that drink or even your saliva. You’re swallowing air too. It lands in your stomach and upper small intestine; some is belched, some absorbed, the rest wiggles through twenty-five feet of bowel wreaking havoc. The fix is at the mouth: slow down, chew, ditch the straw and the bubbles.

Cause 2: Abnormal bowel motility.

Usually this means constipation, always my first suspect when someone comes to me bloated. You can poop every day and still be constipated. Any time poop lingers, it gives gas time to build. One of the gases, methane, is linked with slower transit in people. In other words, slow transit produces gas which slows transit. And round and round we go… Abnormal motility can affect your small bowel and colon. Hydration, movement, and prebiotics are the best place to start. But for many people, that’s not enough. That’s when something gentle and stimulant free, like 38TERA RCE™, comes in handy, which includes GinFort™ (a ginger extract) to support motility in the upper digestive tract along with magnesium oxide to soften stool and Plenibiotic™ to support the microbiome.*

Cause 3: A damaged gut microbiome.

When your microbial ecosystem is out of balance, we call it dysbiosis. Friendly microbes that ferment fiber efficiently get outnumbered by the gassy, angry microbes, and the gut lining grows more reactive. This is a colon problem, and the tools that reach it are a fiber-rich diet, prebiotic supplements like DMN®, and strain-specific probiotics with research behind them.*

Cause 4: Excessive fermentable carbohydrates.

Sometimes your diet is out of step with what your gut can handle right now. FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) are the parts of food your microbes turn into gas. A short, structured low-FODMAP trial can help you figure out if FODMAPs are a challenge for you. But you do not have to eliminate these foods for life. Reduce, reintroduce slowly, find your tolerance, often with a dietitian guiding you. Cutting every fermentable carbohydrate long term is throwing the baby out with the bathwater, and your microbiome pays for it.

Now look at where those four causes land. Swallowed air and the cramping, oversensitive upper gut are felt mostly in the small intestine, fast-moving and nerve-dense, where the problem is movement and sensitivity. Slow transit, microbiome shifts, and fermentation play out in the colon, slower and microbe-dense, where the problem is what your microbes do with what you feed them. Most people with recurring bloating have both involved, which is why single-target fixes disappoint.

Why am I bloated by mid-afternoon when I do everything right?

Your gut has its own nervous system, roughly 500 million neurons in constant conversation with your brain. That conversation sets your gut’s pain dial: how much stretch it takes before your brain acknowledges it as discomfort. In visceral hypersensitivity, gas another person would never notice gets felt as pressure, fullness, even discomfort.

The dial is turned up. It’s like someone blasting your least favorite song on repeat (for me, that’s Cotton Eye Joe by the Rednex), and you just wish someone would turn it down and give your ears some peace and quiet.

The dial turns up with stress, because activation of the sympathetic nervous system also changes gut motility and sensitivity. Other factors; poor sleep, travel, circadian disruption. And for many women — hormones. GI symptoms including bloating increase premenstrually, during menses, and in perimenopause. Visceral pain sensitivity is higher during menses in women with IBS, when estrogen and progesterone levels are low (Heitkemper and Chang, Gend Med 2009, PMID 19406367). Estrogen and progesterone influence how the gut moves and how much it feels. When they decline, the same meals can start producing symptoms they never used to. Many women experience this as they approach menopause.

Why don’t gas drops, enzymes, and cutting foods fix it?

Each targets a small piece of a system problem, and none very effectively.

Gas drops (simethicone) lower surface tension so small, frothy bubbles merge into bigger ones that pass more easily. Basically, that means it’ll be easier to fart. But they don’t touch spasm, motility, the microbiome, or the pain dial.

Digestive enzymes are meant to break down specific food components, but the problem is they’re highly targeted tools. Things like lactase for dairy or alpha-galactosidase for legumes can help in a targeted fashion, but they do nothing for a shifted colon or oversensitive nerves.

Generic probiotics often get hyped and then fail to deliver, which leads to skepticism of probiotics. It’s important to know that probiotics are strain-specific and dose-specific, and grabbing whatever is on the shelf is filling a prescription without knowing what’s in it.

Cutting foods allows you to avoid foods that produce gas. It can help temporarily. But it’s not a good long term strategy because the microbiome grows weaker as you cut things. It’s a little bit like saying you’re going to work out, but you’re not going to work your biceps anymore. At first it’s fine, but eventually it catches up to you when your shoulder starts hurting. So then you stop working your shoulder too, and next thing you know your back is hurting. Restriction is a slippery slope that leads to a weak microbiome.

That is the shrinking food list trap. Remove a food, feel slightly better, and your brain learns “food is the problem, keep removing.” The list shrinks, mealtime anxiety grows, and the plant diversity your microbiome depends on erodes, while the pain dial and fermentation balance driving things go untouched. If you have cut and cut and are still bloated, now you know why.

What does the evidence support for bloating?

The evidence is more specific than “take something for gas.” It points to particular mechanisms in particular places.

Peppermint oil is a natural antispasmodic that relaxes the small intestine’s smooth muscle.

You want it released in the small intestine, where spasm and hypersensitivity live. When you do that, it soothes the gut rather quickly.

Probiotics are meant to support the gut microbiome in your colon. Saccharomyces cerevisiae CNCM I-3856 is a probiotic supported by the World Gastroenterology Organisation’s 2023 probiotic guidelines for IBS symptom improvement. It has two randomized, placebo-controlled IBS trials involving 579 people to support it.

A specific strain at a studied dose, reaching the part of the gut it was studied in, is a different thing than a generic blend.

When should bloating send me to a doctor?

Most bloating is uncomfortable, not dangerous. But there are certain symptoms that, if present, you should discuss them with your doctor. Talk to a clinician if your bloating comes with:

None of these necessarily means something is wrong. They mean something is worth a check in and sooner is always better than later.

What to do next

Your bloating is not one thing, and it does not come from one place.

Take a moment and consider the 4 causes of bloating. Which one fits you?

Ultimately you want to get specific about the root cause of your gas and bloating. Your plan will be to target that cause. For example, if it’s a microbiome issue, DMN® is a microbiome builder.* If it’s sluggish motility, RCE™ was designed to support regularity.* If it’s fermentable carbohydrates, you’ll want to consider FODMAP sensitivity. Good news: 38TERA® is committed to creating FODMAP Friendly products for you.

But with all of these causes, just know that it typically involves both your small intestine and your colon, and that’s exactly why we’ve been working on something new. Coming soon: a product formulated with clinically studied ingredients that work in two distinct locations to help relieve occasional bloating and support digestive comfort.*

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Frequently asked questions

Is bloating the same as having too much gas?

No. Gas volume, visible distension, and the sensation of bloating are three different things. Many people with daily bloating have a normal amount of gas but a gut that senses or handles it differently.

Why is my bloating worse in perimenopause?

GI symptoms including bloating increase at times of declining or low estrogen and progesterone, including premenstrually, during menses, and in perimenopause, and studies in women with IBS suggest visceral pain sensitivity rises when those hormones fall (Heitkemper and Chang, Gend Med 2009, PMID 19406367).

Does peppermint oil work for bloating?

In a meta-analysis of 10 randomized IBS trials, peppermint oil beat placebo for global symptoms and abdominal pain (Ingrosso et al., Aliment Pharmacol Ther 2022, PMID 35942669). A formulation designed to release in the small intestine outperformed placebo in a small IBS trial (Cash et al., Dig Dis Sci 2015, PMID 26319955).

Should I take a probiotic for bloating?

In people with IBS, probiotics as a category have shown benefit for bloating and flatulence (Ford et al., Am J Gastroenterol 2014, PMID 25070051), but effects are strain-specific and dose-specific. Look for a strain that has been clinically studied, and talk to your clinician about what fits your situation.

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.