Why Eat Fiber?

Not just because your grandma said so.

Sexy middle aged woman with cane and derby, standing by a giant apple.

Grandma or grandpa usually knows best when it comes to fiber, but you need lots of fiber at any age.
© Can Stock Photo

Fiber is good for both diarrhea AND constipation. How can that be so? Read on.

Fiber is in many foods we eat, but barely anyone gets the recommended daily amount. But why eat fiber? Why worry about it at all?

Well, insoluble fiber gives your bowels “structure”. In other words, it helps your stool (poop) stick together in a clump inside, and get moved along at a “regular” pace :). Sorry for being graphic.

It also gives your bowels something to grab on to.

Another kind of fiber, called soluble fiber, absorbs water and helps keep things from being too liquid, a blessing for IBS-D. Details below.

Soluble vs insoluble fiber, do I need both?

Soluble fiber is the kind that makes things slippery and absorbs water. That can be a big help for those with bouts of IBS-D or diarrhea.

Insoluble fiber helps keep things together and moving along. It provides some traction for the stool as your body moves it along with peristalsis. That’s great for those with IBS-C or constipation.

Fiber for constipation OR diarrhea???

Sign showing fiber information.

There’s a lot to know about fiber, but what you really need to know is if you’re getting enough!
© Can Stock Photo

Yes, fiber can help either condition. Our bodies are made in such a way that we need a lot of fiber. In the modern diet we just don’t get it.

I think that’s one of the reasons that IBS is often called a developed nation disease.

Can you eat too much fiber?

Changing the amount of fiber in your diet, too much, too fast, can cause gas. Trapped gas can cause bowel spasms and pain. Who needs that!

But if you increase your fiber amounts a little at a time you shouldn’t have much trouble with gas.  Most people get used to increases in fiber after a week or two, and the excess gas goes away.

How many grams of fiber a day?

For women the recommended amount is 25 grams. For men (who usually eat more) the number is 38 grams per day.

That’s a lot of fiber compared to what most people get.  I TRY to get more fiber, and I’m not near 38 grams.

Most people in developed nations are estimated to eat about 15 grams. That’s a lot less than we need to keep things “moving” the way we’d like.

How to increase fiber intake:

By eating things most of us don’t like to eat :(.

Sorry, but it’s true. Most vegetables are a great source of fiber.  But people in developed nations don’t usually eat as many veggies as they should.

I’m a confessed vegetable wimp.

Whole grains like wheat and wheat bran or oat bran have quite a bit of fiber as well. Some of us have trouble with gluten or have wheat allergies though.

I’d love to have a bran muffin right now, but no gluten for me.

Your grandparents called fiber roughage…

A heart shaped pile of bran fiber.

Fiber can be great for your health in other ways. It can help you have a healthy heart and cholesterol for instance.
© Can Stock Photo

And they got a lot more of it than we do.  Even so, most people will never eat the amount of fiber that “cavemen” (or “cavewomen”), ate about 100 grams of fiber a day!

Don’t try to get THERE all at once.

So why eat fiber? Because you’ll suffer if you don’t.

P.S. Grandma was right.

There are all kinds of other things to say about fiber, but I think I’ll write a series about it.

What about you? Any tips about fiber you want to share? Share in the comments section :).



  1. Reply

    I realize this post is 2 years old, but thought the following might add an interesting side to the fiber issue. Note that I am definitely not making any recommendations. I’m only sharing my n=1 details. :)

    Like many readers, I have a history of bowel and gut problems (bloating, pain, constipation, diarrhea, etc.) I began following a meat-fish-and-eggs diet about 12 months ago. Here is a great resource if you care to learn more about it:


    My diet includes beef liver. I happen to like it, despite lots of folks thinking it tastes like dirt. But nutritionally, it’s a powerhouse. I only eat it twice a week (3 or 4 ounces per meal).

    Results: no bloating, minimal gas (often none at all), and no gut pain. Those symptoms only return when I have an occasional junk food item. See Shawn’s post on sugar for the reasons. Also, I have a bowel movement twice a week. I simply don’t need to go.

    You might be thinking, “Wait a second! You only have two bowel movements a week?! Doesn’t meat get stuck in the colon? Doesn’t it start to rot there, causing constipation and pain?” That has not been my experience. My experience is similar to the one described here:


    Here are more details:


    The short version: meat doesn’t make it to the colon. It’s broken down (amino acids, etc.) and its constituent parts absorbed in the small intestine.

    So why do I need to have bowel movements even twice a week? Because fecal matter is composed primarily of water and dead bacteria. Both result from normal digestion.

    Here’s something that will probably make you throw your hands up and declare me insane…

    I don’t consume fiber. Meat and eggs don’t contain fiber. But I do take magnesium supplements. Most of us don’t get nearly enough magnesium. One of its effects is that it tends to pull water into the colon. That’s going to be the case, regardless of the magnesium source.

    If you’d like to learn more about the problems associated with fiber, here’s a fun site:


    Some people call the author a crackpot. Others swear by his recommendations. Again, this is just an n=1 story. Your mileage may vary.

    Also, I use a squatty potty. Search for it on Amazon. It’s a game changer. I’ll leave you to discover the reasons, but suffice to say, it mimics the proper defecation pose used by early humans (and continues to be used in many Asian countries).

    To repeat, don’t take any of the above as recommendations for what you should do. Definitely research things on your own. And don’t automatically assume your doctor knows what’s going on. IBS continues to be a catch-all diagnosis for gut problems that cannot be diagnosed otherwise. Most general practitioners are clueless about how to treat the symptoms. They’re doubly so about how to cure the underlying problem.

    @Shawn – great job on this site.

  2. Reply

    Fiber is terrific, however, introduce slowly and water, water, water. Otherwise you end up with a sawdust plug in your gut.

    • Reply

      That is a very good point, and I’m glad you shared it. I know it’s a serious issue, but the sawdust plug quip was hilarious!!!! Thanks for that very helpful tip Gloria. – Shawn

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