Here’s what happens to food and beverages as they make their way through your gastrointestinal (GI) tract.
How Does the Digestive System Work?
You know what food looks like when it enters your mouth, and what comes out the other end. For many people, though, what happens in between — the journey through your digestive system — can be a confusing process. Take a tour through your digestive system, where we’ll show you what happens from your mouth to your anus.
Check out our digestive system guide to find out more about how our digestive system works.
The time it takes for food to be digested and exit the body can be as short as 10 hours or as long as about 3 days, one study says.
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DID YOU KNOW?
Even before you bite into your food, your digestive system kicks in. There’s a reason why we say “mouth-watering” food. Seeing and smelling food causes an increase in saliva (spit) production, ensuring that your mouth will be ready to chew and swallow what it’s about to receive, the Cleveland Clinic reports. Saliva lubricates your mouth and throat, making it easier to chew and swallow your food and protect your teeth from harmful bacteria. It also contains an enzyme that begins to break down starches, according to the National Institute of Diabetes and (NIDDK).
Mouth
Three major pairs of salivary glands located behind and under your mouth together produce about 1 to 2 liters (or quarts) of saliva every day, cites the Cleveland Clinic. That’s equal to 8 cups a day!
Advanced Symptoms
Your esophagus is a tube that extends from the back of your throat down, near the middle of your abdomen. It’s about 25 centimeters (10 inches) long, according to the National Cancer Institute, and contains muscle that creates a wavelike motion to move food through it — something that happens in much of your digestive tract, notes the (IFFGD). At the bottom of your esophagus, are muscles called the lower esophageal sphincter that opens up when food reaches it, or when you burp, but normally stays closed to prevent food from going back up to your esophagus, the NIDDK states. And if you need to vomit, this muscle will relax while stomach contractions push your food back up.
Esophagus
The urge to vomit doesn’t come from your stomach, but from your brain?
Back to Mouth
When swallowed food and beverages enter your stomach, your stomach muscles get to work mixing them with digestive juices — containing stomach acid and enzymes — that are produced by glands in your stomach lining, the NIDDK notes. Once the contents are mixed thoroughly, a small amount passes through a valve (called the pylorus) into the upper section of your small intestine. This typically happens in portions of 4 milliliters — less than a teaspoon — at a time, according to the Mayo Clinic.
Stomach
Back to ESOPHAGUS
Depending on what you eat, it can take at least 40 minutes or up to 2 hours for food to break down in your stomach. Food that’s high in fat or protein takes longer to break down, the Cleveland Clinic reports.
The small intestine mixes digestive juices from the pancreas and liver, as well as the intestine, and pushes the food down for further digestion. Your pancreas produces enzymes that help digest carbohydrates, proteins, and fats. And liver produces bile, which helps digest fats and is stored in your gallbladder. When fatty materials from food enter your small intestine, your gallbladder releases bile into it through bile ducts, the Mayo Clinic notes.
Small Intestine
Back to Stomach
The average length of a person’s small intestine is about 7 meters (22 feet) — think of four park benches lined up.
Most nutrients and water have already been absorbed by the time your food enters your large intestine (colon) — which is about 1.5 meters (5 feet) long — leaving indigestible parts of food like fiber and dead cells from your digestive tract. The large intestine absorbs nearly all remaining water and certain nutrients, the Cleveland Clinic notes. Helpful bacteria in your large intestine (part of your gut microbiome) break down dietary fiber to produce important nutrients like vitamins B and K, as well as short chain fatty acids for energy, IFFGD notes.
large Intestine
Back to small intestine
When stool enters the final part of your large intestine — your rectum, which is about 15 centimeters (6 inches) long, according to the Canadian Cancer Society — it triggers the urge to have a bowel movement, the Cleveland Clinic says
During a bowel movement, your rectum pushes stool through your anus — a short tube that’s about 4 centimeters (1.5 inches) long. Muscles around your anus (anal sphincters) relax, allowing poop to pass from your body, the Mayo Clinic notes.
Anus
Start Over
The average person farts about 14 to 23 times a day, says the Cleveland Clinic.
