Fiber Is A Double-Edged Sword

Oatmeal fiber gut health gas bloating

Do you have painful gas and bloating?
Do you eat enough fiber?
Do you eat too much fiber?
Do you eat the wrong kind of fiber?

Sounds confusing, doesn’t it?

Fiber is very good for you, but it can also hurt you.

Fiber can cause gut problems such as severe bloating and painful gas. It’s helpful to know about the different kinds of fiber and how they work so that you can make the best choices based on your particular situation.

At the end of this article, I will help you decide which foods to eat and which to avoid for your particular issue. This isn’t a simple process. You may need more targeted direction if you are suffering from painful gastrointestinal problems.

Fiber is confusing because different kinds of fiber act differently in our digestive system. Too much of the “wrong” kind or too little of the “right” kind can cause diarrhea, gas, bloating, and constipation.

"OMG. I thought if I ate more fiber, my constipation would go away! It turns out it got worse. I know you said fiber is tricky but this is crazy. Now, what do I do? "

What is fiber?

Fiber, also known as dietary fiber, is a type of carbohydrate. It is the part of plants (fruits, vegetables, and grains) that we cannot digest. Fiber affects the entire gastrointestinal tract starting in the mouth and ending in the anus. Fiber helps with digestive problems and has other health benefits as well. Certain kinds of fiber are essential for a healthy gut microbiome – your good gut bacteria.

painful gut gas bloating fiber

There are two main categories of fiber: soluble and insoluble.

When it comes to gas, bloating, and abdominal pain, both types of fiber have benefits and drawbacks.

There are two other classifications of fiber you may have heard mentioned in your research. FERMENTABLE and fermentable oligosaccharides disaccharides monosaccharides and polysaccharides otherwise known as FODMAPs. That’s a mouthful!

Although fiber is not digestible, our gut bacteria ferment it, releasing essential byproducts.

Fermentable fiber can be soluble or insoluble. It is good to know this because eating fermentable fiber is the key to building good bacteria for gut health.

Fermentability describes how our gut bacteria break down fiber. The process of fermentation takes place in the large intestine or colon. Fermentable fiber provides energy for our gut bacteria, and they release beneficial byproducts into the body, such as gases and short-chain fatty acids that are essential for our health.

FODMAPs are a more specific type of fermentable fibers. All types of dietary fiber are carbohydrates (sugars). FODMAPs are short chain sugars that digest much more quickly and produce more gas than other fermentable fibers. They are like fast food for your gut microbes. Yet, due to their rapid fermentation, they can be the cause of unwanted gas.

I will cover fermentable fiber and FODMAPs in more depth in another post soon.

Soluble and insoluble fiber. What is the difference?

Every fruit and vegetable has a combination of soluble and insoluble fiber. Some have more of one type of fiber than the other.

Soluble fiber dissolves in water and forms a gel-like substance in the colon. Soluble fiber tends to slow down digestion, allowing more nutrients to be  absorbed. These foods contain predominantly soluble fiber:  psyllium husks, black beans, lima beans, and avocados.

Insoluble fiber (also called resistant starch) does not dissolve in water. It adds bulk to your stools and promotes the passing of material through your digestive system. These foods contain predominantly insoluble fiber: fresh coconuts, figs, prunes, most berries, wheat bran, skins of fruit, whole grains, and dark leafy greens such as kale and spinach.

Soluble and insoluble fiber act differently in the digestive system. Depending on your symptoms, fiber can cause health problems, or it help. Let me  explain.

Is fiber good for you?

It depends!           On what?

Fiber is a vital part of healthful eating; there is no doubt about that.

Whether or not it is good for YOU depends on how much and which type and on your symptoms. There are times when adding more dietary fiber is necessary to reduce symptoms. There are other times when reducing or changing the type of dietary fiber is best to relieve painful symptoms such as gas, bloating, constipation or diarrhea.

The benefits of fiber for everyone.

Studies show adequate fiber intake can reduce your risk of the following diseases:

Heart disease
Certain gastrointestinal disorders (more on this later)

Also, increased fiber intake improves your:

Immune system
Serum lipid concentrations (cholesterol)
Blood pressure
Blood glucose control
Bowel regularity
Weight loss

good gut fiber

The benefits of fiber for gut problems.

Gastrointestinal problems vary widely in cause and symptoms. The following list is from another article I wrote about abdominal pain.

These are the most common conditions that lead to gastrointestinal pain:

All fiber can cause painful gas and bloating if not increased slowly over time.

Most of the above-listed conditions could be alleviated with a higher fiber intake.

There are various reasons why eating a specific fiber can help manage gastrointestinal disorders and ease gut pain.

At the fundamental level, fiber helps either slow down digestion or speed it up.

As I mentioned earlier, soluble fiber absorbs water and becomes gelatinous in the gut. Therefore, it moves through the intestines more slowly and can help with diarrhea. In contrast, insoluble fiber bulks up the stool and passes through more quickly, helping with constipation. Transit time, the speed that digested food matter takes to go from the mouth to the end of the colon and out, is a factor in healthy digestion.

Fiber, beneficial bacteria and gut health.

Another vital benefit of fiber is its impact on your beneficial gut bacteria. I will give you a quick overview and follow up with an in-depth article on fermentable fiber and gut health soon.  

Beneficial or “good” bacteria eat and metabolize (digest) what we eat. The bacteria then produce metabolites or byproducts that are extremely important to our overall health. The primary metabolites are short-chain fatty acids (SCFA), such as acetate, propionate, and butyrate. The known effects of SCFA are intestinal balance, strengthening of the gut lining, and immune effects.

The Drawbacks Of Fiber.

When deciding which fiber-rich foods to eat and how much to eat, you need to experiment. Everyone is unique in the way their digestive system handles fiber, so you will be the best judge of how much is too much and which types of fiber work best for you. I will give you helpful guidelines, but you need to be patient while making daily adjustments to achieve maximum results.

When and How to Choose Which Fiber and How Much.

If you tend towards constipation, the general rule is to eat more insoluble fiber foods.

If you tend towards diarrhea, then eat more foods with soluble fiber.

If you tend to get gas and bloat quickly, I suggest adding fibrous foods slowly and chew them very well. Cooking your food longer than usual to break down the fiber more may also help. 

If You Have Predominantly Constipation

How to get plenty of fiber (including fermentable fiber to feed your beneficial gut bacteria) if you tend towards constipation:

Eat more insoluble fiber. Here is a list of foods with more insoluble fiber: fresh coconuts, figs, prunes, dates, most berries, apples, almonds, whole grains, cauliflower, wheat bran, fruit skins, and dark leafy greens, such as kale and spinach.

If You Have Predominantly Diarrhea

How to get plenty of fiber (including fermentable fiber to feed your beneficial gut bacteria) if you tend towards diarrhea:

Eat more soluble fiber. Here is a list of foods with more soluble fiber: most beans, brussels sprouts, avocados, broccoli, peas, oats, and turnips.


For men: 38g per day
For women: 25g per day
The average person gets about 15g per day 

water fiber hydrate gas bloating

A final note on fluids: Drink plenty of water and non-caffeinated fluids. The more fiber you consume, the more water you need to drink. Fiber absorbs lots of  water.
So drink up!

A trick to getting enough water is to use a big jug or two quart-size mason jars. Measure out at least 2 liters or 8 cups of water in the morning, and be sure to drink it all by late afternoon or early evening.

Bonus tip: There is a natural substance called INULIN that I feel is important to mention. Inulin is especially good at feeding your beneficial bacteria and normalizing bowels. Read this article I wrote about Inulin. 

I recommend you eat more Inulin-rich foods to regulate your bowels. It can work for both loose stools and constipation.

Inulin-rich foods: Jerusalem artichokes, unripe bananas, onions, garlic, chicory root, and asparagus. Google the term Inulin-rich foods for more.

Inulin is also available in powder form. I suggest working up to nine (9) grams of Inulin per day. Take it slowly. Mix it into your water bottle and drink it throughout the day. Do not drink it all at once, or you could wind up with too much gas.

My goal is to give you the information and inspiration you need to make choices that improve your gastrointestinal problems and abdominal pain. It takes some consistency and commitment, yet in the end, it is well worth your time and effort. 

YOU are well worth your time and effort. 
Stay focused. 
Your results will be a great reward.

Be consistent

I am available if you need additional help. Just send me an email, text or call.


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  3. Butt MS, Shahzadi N, Sharif MK, Nasir M. Guar gum: a miracle therapy for hypercholesterolemia,  hyperglycemia and obesity. Crit Rev Food Sci Nutr. 2007;47:389–396
  4. Vos AP, M’Rabet L, Stahl B, Boehm G, Garssen J. Immune-modulatory effects and potential working mechanisms of orally applied nondigestible carbohydrates. Crit RevImmunol. 2007;27:97–140.
  5. Schley PD, Field CJ. The immune-enhancing effects of dietary fibres and prebiotics. Br J Nutr. 2002;87(Suppl 2):S221–S230.
  6. Lindstrom J, Peltonen M, Eriksson JG, et al. High-fibre, low-fat diet predicts long-term weight loss and decreased type 2diabetes risk: the Finnish Diabetes Prevention Study. Diabe-tologia. 2006;49:912–920
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