An illustration showing the small intestines as well as the large intestines, with labels for the different areas, like the small intestine, ascending colon, transverse colon, descending colon, sigmoid colon, appendix, cecum and anal canal. Share on Pinterest

Your intestines are a crucial part of your digestive system. They’re where most of the vitamins and nutrients from food are broken down and absorbed into your bloodstream.
Intestines do a lot of work to help give you the energy and nourishment you need to stay healthy, and to function and thrive every day.
So, have you ever wondered how your intestines work or how long they are? We’ll help you better understand what your intestines do.

What are the small intestines?

Your small intestine runs from your stomach to your large intestine. It continues the process of digestion that started in your stomach.
The small intestine absorbs nutrients and water from digested food. In fact, 90 percentTrusted Source of food absorption happens in the small intestine. What’s left over from this process is then passed into your large intestine.
Your small intestine is divided into three different parts:
  • Duodenum: In the duodenum various enzymes, including those from the pancreas and liver, are used to further break down and absorb partially digested nutrients from the stomach.
  • Jejunum: Further digestion and absorption occurs in the jejunum.
  • Ileum: The ileum absorbs any remaining nutrients that weren’t absorbed in the jejunum. It’s connected to the first part of your large intestine, called the cecum.
A variety of health conditions can affect the small intestine. These include:
  • infections, which can cause gastroenteritis
  • ulcers
  • lactose intolerance
  • irritable bowel syndrome (IBS)
  • celiac disease
  • Crohn’s disease
  • intestinal obstruction

What’s the length of the small intestines?

The length of the small intestineTrusted Source can vary between about 10 feet (3 meters) to over 16 feet (5 meters). For comparison, a standard basketball hoop is 10 feet tall.
The different sections of the small intestine are also different lengths. The ileum is the longest section while the duodenum is the shortest.
Since it’s so long, you may wonder why the small intestine is called “small” in the first place. This terminology actually refers to the diameter of the small intestine, which is about 1 inch (around 2.5 centimeters).
Despite its small diameter, the small intestine actually has a very high surface area. That’s because its walls are actually covered in folds and hair-like projections. This increased surface area allows for more absorption of nutrients and water.

What are the large intestines?

Your large intestine runs from your small intestine to your anus.
It absorbs water and electrolytes from the food you’ve eaten. Any remaining food products that aren’t absorbed in the large intestine become stool.
Additionally, bacteria found in the large intestine can help to further break down any remaining nutrients. Vitamins such as vitamin K are also produced in the large intestine.
Like the small intestine, the large intestine consists of several different parts:
  • Cecum: The cecum receives food from the small intestine. It’s involved in absorption of water and electrolytes.
  • Colon: The colon consists of several parts — the ascending colon, transverse colon, descending colon, and sigmoid colon. Like the cecum, it absorbs water and electrolytes.
  • Rectum: Undigested food material moves from the colon to the rectum. The rectum holds stool until it can be eliminated from the body.
  • Anus: Stool passes through your anus and out of your body when you have a bowel movement.
There are also some specific health conditions that can affect the large intestine. Some of the most common include:
  • constipation
  • diarrhea
  • infections, which can lead to colitis
  • ulcerative colitis
  • Crohn’s disease
  • irritable bowel syndrome (IBS)
  • diverticulitis
  • colorectal cancer

What’s the length of the large intestines?

The large intestine is about 5 feetTrusted Source (1.5 meters) long. If you stretched out your large intestine, it would be about as long as the width of a queen size bed.
The colon is the longest portion of your large intestine. The other parts — the cecum, rectum, and anus — are all much shorter, only a few inches in length at the most.
The large intestine also has a larger diameter than the small intestine. It’s about 3 inches (around 7.6 centimeters) wide.

The takeaway

Together your small and large intestines are about 15 feet or more in length.
According to a 2014 studyTrusted Source, the total surface area of your intestines is about half the size of a badminton court.
Your intestines have the very important job of helping to break down and absorb nutrients from what you eat and drink. Once these nutrients are absorbed, they can be delivered via the bloodstream to the rest ofour body.