What Causes Bloating?

“I feel like I’m nine months pregnant, it’s embarrassing”

“As soon as I eat it’s like I blow up like a balloon”

“I can’t do my pants up by the end of the day”

These are things real people say about the real digestive issues they’re facing.

You may be thinking:

“Well it’s obvious what causes bloating – it’s because I have too much gas”. However, that’s not often the case. And in today’s article I’ll break down why that is. We’ll explore the finer details of what causes bloating. More importantly, we’ll discuss what you can do about it.

What Is Bloating?

Bloating is a digestive symptom described as an uncomfortable feeling of too much gas or a stretching of your intestines. It is just a sensation. Often when patients tell me they’re bloated what they’re really describing is when their belly sticks out, physically expands or stretches to the point you can see it. This is known as distention.

The two often overlap, meaning you may feel bloated and look distended. That’s pretty common. But it’s not always the case.

What Causes Bloating?

Bloating has many different causes. It can be a symptom of pretty much any digestive disorder like irritable bowel syndrome and inflammatory bowel disease. It can also be a sign of hormonal changes and even cancer.

Yes, having too much gas in your gut can be one of the causes of bloating. But studies say it’s not the only cause. And it may not even be the most common cause. Speaking of which, today I’ll be covering the top 5 causes of bloating.

Sensitive Nerves In The Gut

We all produce gas in the intestines. No one is exempt from this. Some of us produce more than others. We are like small batch breweries. Without the fancy craft beer, of course.

So why do some people feel like they have more gas in their gut than the average person? It’s because of a phenomenon called visceral hypersensitivity.

When the nerves in the gut become sensitive, they start to feel things more strongly. They may feel gas when there is little. They may feel a lot of gas when there is a normal amount. An amount most other people wouldn’t even be aware of. When their bowels stretch, even a bit, it’s as if someone blew up a balloon inside them. This is visceral hypersensitivity in a nutshell.

• Sound like you have visceral hypersensitivity? Learn more
• Told you have IBS? Here’s what else it could be

This happens with trauma, chronic stress and infection. And it directly affects the nerves in your gut. Again, this doesn’t mean you make too much gas (although you might).

Abdominal Reflex

Believe it or not our abdominal wall (our abs) play a big role in gas mechanics. So does our diaphragm. They’re supposed to play nice with each other. Normally, they perform something called the abdomino-phrenic reflex (phrenic=diaphragm). The reflex is when the diaphragm relaxes and the abs contract after you eat a meal.

Mechanically speaking, this helps to push things (gas among them) down the tube. For some reason, which we don’t understand yet, those with chronic bloating & distention have an altered reflex. Basically, the opposite of what is supposed to happen happens. And the end result is that gas gets pushed into pockets of the digestive tract and it causes the abdominal wall to relax. Let your abdominal wall relax right now and see what happens… Like really let it go. Now picture you felt like this all day. Some people do.

This backwards reflex leads to your belly sticking out and is thought to be a big cause of bloating and distention. Not the gas itself.

There’s good news. Because this is a mechanical problem, it has a mechanical solution.

Enter Biofeedback Therapy. Biofeedback uses electrodes to sense your muscle activity while a trained professional helps you retrain your muscles in real-time. Studies on biofeedback are quite positive for those with chronic bloating and distention.

And don’t fret if biofeedback isn’t an option for you. It turns out there is a simple, yet effective technique you can perform by yourself right at home. It’s called diaphragmatic breathing.

Small Intestinal Bacterial Overgrowth (SIBO)

Ok, so here’s the part where I tell you, you may actually have too much gas. Or at least too much gas in the wrong place. The small intestine to be specific. With small intestinal bacterial overgrowth, or SIBO, you have too many bacteria in the small intestine. And the most common symptom of SIBO is bloating.

It’s more complicated than that but what you have to know is that bacteria ferment our food. They do this so that they can produce another type of food for our colon. Isn’t that nice. However, they aren’t supposed to do this until food reaches the large intestine (colon). With SIBO, you have a lot of bacteria in the small intestine so the party starts early. When food is fermented, different types of gases are formed. These gases can cause the bowels to stretch and now you’re bloated.

Altered Gut Motility (impaired gas clearance)

Gut motility, in the simplest terms, is the movement of stuff through the digestive tract. More specifically, it is how effective muscular contractions are at moving said stuff through the intestines. Stuff includes things like bacteria, poop, fluids and yes, even gas through the intestines. Slow motility is generally seen in constipation. This makes sense. If our bowels can’t push things out effectively and in a timely manner then we get backed up. Surprisingly, not all types of constipation have slow motility. On the other hand, with fast motility, we may have the opposite problem – diarrhea.

Let’s bring it back to the gas though.

We know that gut motility helps us release gas mainly through flatulence. We can also belch to relieve ourselves. It’s always healthy to have options! If our motility is slow or damaged then it becomes harder for us to clear gas. Gas, if it’s not re-absorbed, will sit and build up in your gut. This causes your bowels to stretch. This causes sensations like bloating or pain if it’s bad enough. Again, it’s not necessarily the total amount of gas that’s the issue. Rather, here it’s the speed at which it leaves the body.

Acupuncture and herbs like ginger, caraway and peppermint can be helpful for promoting healthy gut motility.

Carbohydrate Intolerance

Carbs. We love em, we hate em. The carbohydrates I’ll be referring to are monosaccharides and polysaccharides. These are single sugars or sugars linked/bonded to one another.

These are glucose, lactose, fructose, and sucrose. When we consume these – especially in large amounts – and we either don’t break them down or absorb them properly, they can cause issues like gas and bloating. This is the definition of carbohydrate intolerance.

There are several causes of carbohydrate intolerances.

One dietary approach that recognizes these common carbohydrate intolerances is a Low FODMAP Diet. The diet aims to reduce the consumption of these products to limit their fermentation by bacteria.

Studies show it can be greatly helpful for those suffering with irritable bowel syndrome. One of the symptoms that improves with the diet:

Bloating.

It seems to work in those who are not high gas producers as well. Why? Because it reduces the amount of gas production – even a normal amount – below levels the nerves can detect – even sensitive ones.

The major downside of the diet is that it restricts healthy foods and vegetables we love like garlic, onions and brussels sprouts. Everyone loves brussels sprouts right?!?

This may have unintended consequences on the gut bacteria. As many of these foods the diet restricts actually feed healthy bacteria too. Either way, you should never have to restrict your diet for life. Done well, this can be a great way to tailor your diet, while minimizing symptoms and working on the underlying causes.

Learn more about the Low FODMAP Diet

I’ve Already Changed My Diet

And sometimes, it’s not your diet’s fault. I work with many patients who have been on restrictive diets for years to control their bloating when they come to see me. There’s usually an underlying cause they’re not addressing. And restricting more foods isn’t the answer.

That being said I am a big fan of what the Low FODMAP approach can do in the short term for symptomatic relief. It’s just not where your plan should end.

Why Is Bloating So Tough To Get Rid Of?

As you can imagine someone may have all of the problems mentioned above. They may have developed SIBO as a result of an infection. Now, because of the infection and SIBO, they have carbohydrate malabsorption. That infection may have also caused nerve damage, leading to both visceral hypersensitivity and impaired gut motility. Now their gut is sensing more gas (bloating), generating more gas, and is unable to clear it. It happens and I see it often.

The point i’m trying to illustrate here is that it’s complicated. It’s not as simple as taking a probiotic, peppermint oil supplement or Gas-relieving medication and hoping the problem resolves itself. It requires identifying the cause(s) and addressing them.

References

Lacy, Brian E., David Cangemi, and Maria Vazquez-Roque. “Management of Chronic Abdominal Distension and Bloating.” Clinical Gastroenterology and Hepatology (2020).

Mari, Amir, et al. “Bloating and Abdominal Distension: Clinical Approach and Management.” Advances in therapy 36.5 (2019): 1075-1084.

Barba, Elizabeth, Anna Accarino, and Fernando Azpiroz. “Correction of abdominal distention by biofeedback-guided control of abdominothoracic muscular activity in a randomized, placebo-controlled trial.” Clinical Gastroenterology and Hepatology 15.12 (2017): 1922-1929.

Li, Hui, et al. “Acupuncture and regulation of gastrointestinal function.” World Journal of Gastroenterology: WJG 21.27 (2015): 8304.

Krueger, Dagmar, et al. “Peppermint and caraway oils have muscle inhibitory and pro‐secretory activity in the human intestine in vitro.” Neurogastroenterology & Motility (2019): e13748.