woman touching a screen that shows human intestinal track

About our Digestive System

Your digestive system is made up of the digestive tract – a long unbroken “tube” that extends from your mouth to your anus (gum to bum as we call it!) – and other abdominal organs that play a role in digestion such as the liver and pancreas.

The digestive system is complex and full of surprises.

Fun Facts about the Digestive System

The 5 Stages of Digestion

The 5 stages of the digestive system are:

  1. Ingestion (Taking food into body)
  2. Digestion (Breaking food down)
  3. Absorption (Moving food into cells)
  4. Assimilation (Making food part of cell)
  5. Elimination (Removing unused food)

When working well, the digestive system breaks down the food we eat into nutrients the body can absorb. In humans, proteins are broken down into amino acids, starches into simple sugars, and fats into fatty acids and other small molecules. The bloodstream distributes these nutrients to the rest of the body, and waste products are passed out as feces. Depending on what you’ve eaten, it can take anywhere from several hours to several days to fully digest food.

How Things Go Wrong

Every section of the digestive tract is prone to specific disorders – some of them a mere nuisance, others highly disruptive, and still others potentially fatal. In some cases, getting tested and diagnosed early can reduce or eliminate the need for treatment. Even if long-term treatment is required, today’s treatment options and management strategies make it possible to control the symptoms of most digestive disorders – and in some cases, to prevent their progression.

The diagram below illustrates some of the factors that may contribute to digestive problems or aggravate digestive conditions that already exist.

Smoking can harm all parts of the digestive system, contributing to such common disorders as heartburn and ulcers. Smoking also increases the risk of Crohn’s disease and (especially in women) appears to raise the risk of gallstones.(4) Consuming alcohol, meanwhile, worsens heartburn and diarrhea. (5)

It was once thought that stress could actually cause certain digestive disorders, such as peptic ulcers. We now know that stress doesn’t cause ulcers to develop, though it can certainly worsen an existing ulcer. Increased stress can also trigger a flare in Crohn’s disease, ulcerative colitis, and irritable bowel syndrome (IBS). (5)

Certain medications may cause either transient or persistent digestive symptoms. In some cases, the symptoms can be counteracted with other drugs. Missing doses can also increase symptoms or complications of digestive disorders, so it’s important to take your drugs as prescribed. (5)

Most people in good digestive health have a healthy weight and don’t regularly experience symptoms like heartburn, gas, constipation, diarrhea, nausea or stomach pain. If you’re experiencing such problems on a regular basis, learn more about what may lie behind your symptoms. If you have blood in your stool, unexplained loss of weight or appetite, or a sudden change in your bowel habits, see your doctor as soon as possible.

Why Gut Health Matters

How Healthy is your Digestion?

On the other hand, some indicators of not-so-healthy digestion:

Watch the video from NutriProCan Dietitian Lisa Spriet below to learn all about gut healthy foods, supplements (probiotics, prebiotics, etc), and other lifestyle factors that improve gut health.

If you have a digestive condition, you are not alone

Digestive disorders touch the lives of millions of Canadians every year. Because few people speak openly about their digestive symptoms, the magnitude of the problem is not fully appreciated. The devastating impact of diseases such as cancer and heart disease is well known to many Canadians.

What fewer people may realize is that digestive diseases have at least as great an impact on our society and its individuals. Some digestive disorders, such as colon cancer and inflammatory bowel disease (IBD), can shorten life. On the whole, however, digestive disorders tend to have a greater impact on the quality of life than on its duration. Most digestive diseases strike people during their most productive and energetic years, severely disrupting employment, leisure activities, finances, personal relationships, and family life.

Digestive Condition Alarm Symptoms

Digestive symptoms may stem from a temporary illness such as a flu, a reaction to certain medications, or a more chronic underlying condition.

The following symptoms signal a problem that requires prompt medical attention:

If you have these alarm symptoms, your family doctor may refer you to a gastroenterologist – a doctor who specializes in the diagnosis and treatment of diseases affecting the digestive system.


  1. MediLexicon International. (n.d.). Gut microbes important for serotonin production. Medical News Today. Retrieved January 13, 2022, from https://www.medicalnewstoday.com/articles/292693
  2. Carpenter, D. S. (2012, September). That gut feeling. Monitor on Psychology. Retrieved January 13, 2022, from https://www.apa.org/monitor/2012/09/gut-feeling
  3. Health Canada; Fibre (2019, January 22). Government of Canada. Retrieved from https://www.canada.ca/en/health-canada/services/nutrients/fibre.html 
  4. Smoking and your digestive system. National Digestive Diseases Information Clearinghouse.
  5. Cross R. Avoiding digestive health problems. University of Maryland Medical Center. www.umm.edu/ibd/digestive_health_problems.htm
  6. Fermented Foods. (n.d.). Retrieved from https://isappscience.org/for-scientists/resources/fermented-foods/