How Does the Digestive System Work?

How Does the Digestive System Work?

The health industry is rife with words like “detox” and “optimal health.” There’s a lot of talk about the importance of making sure you have a healthy working digestive system and it’s well acknowledged that the gut is often at the root of disease.

We’ll be the first to tell you about any and all of those (in fact, we have articles and products that help) but we’ll also be the first to tell you the knowledge is power. We believe fully that you deserve to be in control of your own health—and the best way to achieve that is to know what you’re working towards.

You can read every article about ways to get your digestive system on track, but if you don’t know the signs of optimal digestion, you won’t be able to recognize the signs of dis-ease. We don’t want you blindly detoxing because an article piqued your interest or flushing out your liver when you don’t need to (there is such a thing as overdoing it). We want you to know what you’re dealing with in your own body so you know when to take action for your health.

So, over the next few months, we will be walking you through how your ideal body should function, starting with the digestive system. This article will cover how the digestion works, next week we'll talk about common issues and tips to keep it healthy.

How Your Digestive System Should Work

The basic function of our digestive system is to break down the food that we consume into energy that nourishes our body.

Seems simple, yeah? Well, it’s actually pretty complicated, but we’ll try to make it easy to understand here.  

How Food Travels Through the Body

Where does digestion start? If you said, “in your mouth” you would be right. Although there is an argument that digestion starts before that with your other senses—like when you see a donut in the window of the shop or when you smell turkey dinner and you’re drooling over how good you know it will be.

Upper GI

Physically though, your mouth starts digestion with the release of saliva. Healthy saliva has enzymes that start the breakdown of carbohydrates immediately. It also helps to remineralize your teeth and has an antimicrobial effect on your gums. When your mouth starts to salivate, it signals to your body “Hey! We’re going to have some food!” and your stomach releases its own secretions. (Note: we didn’t say this article was going to be pretty.)

So you’ve adequately chewed your food—some people need to be reminded, you know—and swallowed, the food travels down the esophagus, basically just a muscular tube, and into the stomach.

This is where it gets good.

The stomach, stewing in its own unique microbiome, secretes hydrochloric acid and an enzyme called pepsin, which kills pathogens in food and helps to break down proteins into individual amino acids. Here the stomach mechanically and chemically breaks down food into an unrecognizable mass called chyme. That process of churning and fermenting stimulates the release of hormones in the small intestine.

Lower GI

The first part of the small intestine is called the duodenum. The duodenum is important because it acts as a neutralizing zone—remember that the stomach uses a highly corrosive acid to break down food, it’s still very acidic when it enters the duodenum, which isn’t well tolerated in the rest of the body. So, in order to balance the acidity, the pancreas releases bicarbonate into the duodenum. (I know, we’re like a verifiable science experiment.)

Then, still in the duodenum, the gallbladder releases bile to emulsify the fats in the chyme while the pancreas and liver release enzymes that help further breakdown macronutrients (fat, protein, carbs) to their most basic units. Here things split off into two directions, macronutrients go to the liver through the portal vein and everything else continues through the lower GI.

The liver has a whole slew of amazing functions including organizing useful nutrients, cleaning out the toxins (and sending them off to be disposed of properly), detoxifying the metabolites, maintaining the balance of fats and carbs, storing glucose as glycogen for further energy supply, and feeding the tissues in the body.

Meanwhile, the remaining chyme is being pushed through the rest of the small intestine and the body is pulling vitamins and minerals from it. In the lower part of the small intestine, vitamin B12, folic acid, essential fatty acids, vitamins A,D,E and bile are absorbed into the bloodstream.

What’s left of chyme is then pushed into the large intestine, where intestinal flora breakdown the chyme even further and more folic acid and vitamin K is absorbed. At the very last stage, the colon pulls out excess water, chlorine, and sodium from the chyme, turning it to feces, which exits the body via the rectum.

Your digestive system is one of the most complex because it involves so many different organs, but it's straightforward function is to collect and filter nutrients from food in order to supply energy to the rest of your body.

This process should take 16 to 24 hours, and you should have 1-3 regular bowel movements everyday.

Digestion Homework

Oh no—I didn't tell you that you'd have homework! Don't worry, it's easy. Maybe you already know this and you're done, but spend the next few days paying attention to your digestion. There's nothing to write down, just take note of your body's messages.

When do you feel hungry?

Are you prone to constipation or diarrhea?

Are you working with bloating, gas, acid reflux or another chronic issue? If yes, when does that occur (time of day and after what type of food).

Do you have a regular bowel movement cycle?

Our next article will tell you about the causes of common issues in the digestive system along with tips to promote your health.

Are you learning about the digestive system? Tell us your favorite fun fact in the comments below! 



Gray, H., & Pick, T. (1977). Anatomy, descriptive and surgical (Rev. American, from the 15th English, ed.). New York: Bounty Books.

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Prateek Sharma

Prateek Sharma

Acidity and junk food habits are getting a lot common these days.With these situations leading to many stomach issues
what is acid reflux



acid reflux is the acidity you face when you don’t get enough food on time.Here’s a description of what is acid reflux and its affect on stomach

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