Your Digestive System

Great health and vibrant energy start with a healthy digestive system

Your digestive system powers your health
A healthy digestive system underpins
vitality and outstanding health.

The nutrients in your food provide both the energy that fuels your life, and the building blocks needed to continuously maintain your physical body in its peak condition.

It's your digestive system that extracts the nutrients from your food and absorbs and assimilates them into your body.

A healthy digestive system is necessary to maximise your nourishment from the food you eat.

Nourishment is the source of life. The quality of your nourishment is what determines your ability to live and love to the full, and to look and feel great.

And it's not just what you eat that matters (though that's crucial).

For optimum nourishment you need to keep your digestive system in peak performance.

But mostly we take our digestive system for granted.

Because digestion happens more or less automatically, without our conscious thought or intent, we mostly don't even think about it.

We overload ourselves with food and drink taken on the run and under stress, and wonder why we end up feeling down and depleted of energy.

Poor digestion is a misery.
The symptoms of indigestion are unpleasant and all too common.

We all know what it's like when our digestive system is not working properly.

The symptoms of indigestion are all too common. A burning sensation in the upper abdomen, abdominal pain, belching, flatulence, vomiting, heartburn, bloating of the stomach and nausea - we've all experienced them.

Of course these symptoms can indicate a more serious health condition. If they persist or if for any reason you're worried about them, seek professional advice. Self diagnosis and medication can be unwise.

But more often than not, stomach problems are self-inflicted. We overeat, drink too much alcohol, mix incompatible foods or eat foods that 'don't agree' with us. We eat too many unhealthy foods - 'junk' foods - and we rush them down while stressed and on the run.

We can blame only ourselves for our tummy troubles.

And we ought to know better. We all know from experience that when we mistreat our digestive system it gets back at us. This is certainly one body system that knows how to communicate.

Clearly it's got something important to say.

Learn to listen to the wisdom of your body. Your health depends on it. Symptoms are signals that all is not right. And when all is not right with your digestive system, you need to know.

We're easily tempted to overeat. Our bodies evolved at a time when the steady availability of food was by no means certain. We had to cope with cycles of feast and famine, so in good times we needed to eat enough to tide us over. We stored the excess calories as body fat (we still do!) until needed.

Too much food leads to indigestion.
We're easily tempted to eat more than we can comfortably digest. We pay the price.

But if your digestive system can't cope with your current food intake - what you eat and drink, how much and how quickly, in what mixtures and under what conditions - your digestion simply won't work properly.

It won't extract the full nutritional benefit of your food. Your body won't get the nourishment it needs to serve you faithfully and well, and to keep on going.

Clearly this is critical for your health and vitality. It seems only natural that your stomach should be programmed to kick up a stink when you neglect its needs.

The better your digestive system works, the better the use your body can make of the nutrients in your food. The healthier you will be. Good, healthy digestion is crucial to provide you with great levels of energy and vitality, productivity and creativity. And it will help ensure your longer term prospects for lasting health and longevity.

I'm not just talking about avoiding stomach upset or other stomach problems. Efficient and effective use of the nutrients you offer your body is fundamental to all aspects of heath.

Let's just take a brief look at your digestive system, what it does and how it works. This brief overview will help you understand how you can help your digestive system to work better for you. Your body will love you for it.

Your digestive system

Your digestive system takes the food and drink you put into your mouth, and breaks it down into its smallest units (amino acids, simple sugars and fatty acids). This enables the fats, sugars, vitamins, minerals and other nutrients in your food to be absorbed into your bloodstream and carried to cells throughout your body.

There they're reassembled into the materials your body needs to provide the energy for both your conscious activities and your unconscious automatic body processes such as pumping your blood, breathing and maintaining your body temperature. Digestion of your food also supplies the raw materials needed for your body's maintenance and growth.

Finally, undigestible material (fibre and some starches), is prepared for elimination as faeces.

It helps to think of your digestive system as having two parts - a digestive tract through which your food passes to be processed, and a group of accessory organs that provide the chemical substances - acids and enzymes - needed for digestion to take place. Let's look at each of these.

The digestive tract

Your digestive tract (also called the gastrointestinal tract) is basically a long muscular tube that starts at your mouth and travels down through the oesophagus, stomach, small intestine, large intestine, and rectum, finishing at the anus.

And I mean it's long! For the average person it's about 9 metres (30 feet) in length. Its full of twists and turns as it coils around and about on itself to fit snugly inside your body.

The food you eat travels through this tube, is 'digested' along the way, and then absorbed into your bloodstream through the walls of the tube.

The accessory organs of digestion

This is a group of specialised cells and organs, which produce and secrete digestive enzymes into the digestive tract. Several of the digestive glands are located in the walls of the digestive tract. Others, for example the salivary glands, pancreas, liver and gallbladder, are located outside the tract but secrete into the digestive tract through small tubes called ducts.

The digestive system performs five important functions.


This is the first step in digestion. It's when you take food or drink into your mouth.

Movement of food

Once the food leaves your mouth, waves of muscular contraction continually push your partially digested food along through the various sections of the digestive tract. The process is called peristalsis.


The breakdown of the food by both mechanical and chemical processes that began in your mouth, continues once the food reaches your stomach. Most of the digestive action takes place in the stomach and, especially, in the small intestine.


The small units into which your digested food has been broken down, pass through the walls of the digestive tract, moving from the digestive system into the bloodstream for distribution to your cells and organs throughout the body.


Some components of your food are indigestible substances. Dietary fibre is an example. These substances travel the entire length of the digestive tract, and are ultimately eliminated as faeces.

The Digestive Tract

There are five major parts to the digestive tract.

The Mouth

The work of the digestive system actually begins in the mouth, where you begin the digestion process of breaking the food down into smaller components. You do this in two ways.

  • Mechanically. The first thing you do when you put food into your mouth is attack it with your teeth. You bite, grind and chew your way through it until it's ready to swallow. This is called mastication. Your tongue helps in this by acting like a tumbler to move, churn and reposition the food between our teeth and against the roof of your mouth (your palate). The process of chewing our food is the only process within the digestive system (other than choosing when to defecate) that you can control consciously.

  • Chemically. This is an unconscious, automatic, process. Your salivary glands infuse of saliva which mixes with your food and begins the process of chemically breaking it down.

After you chew your food you swallow it. Swallowing is actually an automatic reflex that occurs when you have finished chewing and pass the mass of chewed up food to the back of the mouth into the opening of the pharynx. The mass of food that has been chewed and swallowed is called a bolus (from the Latin for a ball).

The Oesophagus

This is a muscular tube connecting the mouth with the stomach. It's about 25 centimetres (ten inches) long in the average person. The mouthful of food you have just chewed and swallowed, the bolus, moves down through this tube pretty quickly, helped by the action of peristalsis and by gravity (unless you're lying down!). The role of your oesophagus is simply to get your food down into your stomach, where the processes of your digestive system begin in earnest.

The Stomach

This is where the real action begins. The average person's stomach has a capacity of about one litre (approximately four cups). When the stomach receives food, it is swept by powerful waves of muscle contraction. These waves churn and mix the bolus as it arrives, causing it to break down into smaller and smaller particles.

After a while these particles are moved, little by little, down from the upper to the lower portion of the stomach. Here juices containing hydrochloric acid and other enzymes are added to the food and it is ground into a semi-liquid mass called chyme.

A stomach enzyme called pepsin combines with the strong stomach acid to uncoil proteins and partially break them down.

The strong acidity of the stomach prevents bacterial growth and kills most bacteria that enter your body with food.

The stomach releases the chyme bit by bit through a the pyloric sphincter, a valve which opens into the small intestine and then closes behind the chyme.

The Small Intestine

Most of the absorption of nutrients into the bloodstream takes place in the small intestine. It's a long narrow tube, typically up to 3.5 metres (about 11.5 feet) long and about 2.5 centimetres (about an inch) in diameter.

When partially digested food enters the small intestine from the stomach, its acidity stimulates the both pancreas and cells of the small intestine to release a number of different types of digestive enzymes into the intestine. These enzymes play an important role in digestion. They assist chemical processes that break down carbohydrates, fats and proteins into molecules small enough to be absorbed through the wall of the small intestine into the blood.

In addition, the pancreas secretes sodium bicarbonate. This is a strongly alkaline substance that neutralises the acid from the stomach.

The entry of food (particularly fat) into the small intestine also causes the secretion of bile, which has been produced by the liver and stored in the gall bladder. Bile is not an enzyme. It is a complex solution of salts and other substances. Bile breaks large fat droplets down into much smaller droplets, which in turn allows the digestive enzymes to break down fats more effectively.

Food remains in the small intestine for somewhere between three and ten hours. By the time it has reached the end of the small intestine some 95% of the nutrients that were in the food will have been absorbed into the blood.

The digestive system receives about 9 litres of water in a typical day. However generally that includes only about 2 litres of dietary fluid. By far the main source of water in the digestive tract - about 7 litres - comes from digestive system secretions. The small intestine is also responsible for 85-90% of the water absorbed from the digestive system. Only about 1.5 litres of water remains in the still undigested material that passes from the small intestine to the large intestine.

The Large Intestine

The remnants of digestion that enter the large intestine are the remaining water, some minerals and undigested fibres and starches. Only a minor amount, around 5%, of carbohydrate, protein and fat generally escapes absorption from the small intestine.

The large intestine is a wider tube than the small intestine, but ii's only about 1.1 metres (3.6 feet) long.

The large intestine mainly absorbs sodium and potassium, along with some water, leaving only about 0.2 litres of water unabsorbed.

Bacteria living inside the large intestine ferment different dietary fibres and undigested starches to produce short-chain fatty acids. Many of these are actually used by the cells of the large intestine as an energy source.

Bacterial fermentation inside the large intestine also produces vitamin K and biotin (a B-group vitamin).

Food generally takes about 24-72 hours to pass through the large intestine. Occasionally the intestine becomes irritated and peristalsis moves material through it too fast for enough water to be reabsorbed into the bloodstream from it, causing diarrhoea. On the other hand, if material moves through the large intestine too slowly, too much water is reabsorbed from it, and constipation is the result. An adequate amount of dietary fibre should provide the bulk needed to stimulate enough peristalsis in the large intestine to prevent constipation.

The last part of the large intestine, the rectum, serves as a storage chamber for the faeces until defecation takes place through the anus.

More on Healthy Nutrition

Knowledge is the key to taking personal responsibility for your health. Learn how to Nourish your body for outstanding health. Use these 10 healthy eating tips for optimal nourishment.

Discover how modern scientific studies have overturned traditional notions of a 'balanced diet' based on the Five Food Groups and the Nutrition Pyramid.

Soar through life with the 6 Healthy Habits

  1. Live Consciously
  2. Act Responsibly
  3. Grow Authentically
  4. Nourish your Body
  5. Nourish your Mind
  6. Nourish your Soul

Achieve Lasting Change NOW.

  • outstanding physical, mental and spiritual health
  • well-being, prosperity, inner peace and life purpose.

"Take charge of your health."

"Take control of your life."

"Do it Now."

See Also

The 6 Healthy Habits

The 6 Healthy Habits

Revolutionary new knowledge: Maintain ideal weight, health and fitness, beat stress, look and feel great.

Natural Ideal Health

Natural Ideal Health

Real health, far superior to what we accept as 'normal.'

Become physically, mentally and spiritually vital.

Healthy nutrition

Healthy Nutrition

Enjoy greater health, vitality and energy than you thought possible.

Get the nutrients you need for outstanding health.

Healthy Aging

Anti aging

Slow down your aging clock. Avoid diseases of aging; maintain your physical and mental powers for a long, active and healthy life.



Stress is common and harms your health.

Learn how to deal with it.

Self Improvement

Self improvement

At last, modern research reveals personal change strategies that really work.

You can achieve genuine, lasting change NOW.