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Colon Cancer

About the Colon and Rectum

What they are, what they do, and why they're important

What are the colon and rectum?

The colon and rectum form the large bowel or large intestine, which is an organ that is part of the digestive system (also called the digestive tract). The digestive system is the group of organs that allow us to eat and to use the food we eat to fuel our bodies.

What do the colon and rectum do?

The colon and rectum play a very important role in how our bodies use the food we eat. Here is how food travels through the body:

1. Food begins in the mouth where it is chewed by the teeth into smaller pieces. The salivary glands release juices to help, and the tongue and saliva turn the food into even smaller pieces that will fit into the esophagus. The esophagus is a 10-inch-long tube that connects to the stomach. Muscles in the esophagus move food into the stomach.

2. In the stomach, gastric juices - protein substances called enzymes - break down the food into smaller bits. The stomach has powerful muscles that churn up the food until it's a creamy liquid. This material moves into the small bowel.

3. In the small bowel (22 feet long), the food particles get even smaller. More juices from the pancreas, liver and gallbladder mix together in the small bowel. Here is where all the important vitamins and nutrients in food move through the blood vessels that are in the lining of the small bowel. The blood takes the nutrients to other organs in the body. The nutrients are used to help repair cells and tissue.

4. What is left over, which is mostly liquid, then moves into the colon (5 feet long). The water is absorbed in the colon. Bacteria in the colon break down the remaining material. Then the colon moves the leftover material into the rectum.

5. The rectum is like a storage-holder for this waste. Muscles in the rectum move the waste, called stool, out of the body through the anus.

Why are the colon and rectum important?

Healthy eating is good for your overall health, but having a low-calorie, high-fiber diet that includes many fruits and vegetables is important to a healthy colon and rectum. A healthy colon and rectum will rid your body of the leftovers it no longer needs. Your stool is filled with bacteria, so it is important to pass this out of your body. If your colon or rectum aren't working the way they should, you will experience problems such as bloating, gas and pain.

Educate yourself and the ones you love

March is National Colorectal Cancer Awareness Month, founded by the Cancer Research and Prevention Foundation. Colorectal cancer is preventable, and is easy to treat and often curable when detected early. Talk with your health care professional about colorectal cancer today.

This content was taken from the 2007 NCRCAM Tool Kit and was adapted for use on NetWellness with permission, 2007.

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Last Reviewed: Aug 23, 2010

Tanios   Bekaii-Saab, MD Tanios Bekaii-Saab, MD
Assistant Professor of Medical Oncology
Associate Professor of Pharmacology
College of Medicine
The Ohio State University