A colonoscopy is a common procedure to check the health of your colon. A colonoscopy can find the cause of problems, such as changes in your bowel movements, bloody stool, belly pain, and weight loss. And it can find colon cancer early, when it's most treatable.

The colon is commonly known as the large intestine. It's a hollow tube that runs between your small intestine and your rectum. The food you eat travels through your colon, where nutrients and water are absorbed. The leftover waste becomes stool that exits your body through the anus.

Your colon is shaped a bit like an upside-down letter "U" with a tail at the end. The part that travels up the right side of your abdomen is called the ascending colon. As it crosses the body under your liver, it is called the transverse colon, and the part that turns and goes down the left side of your abdomen is called the descending colon. The sigmoid colon bends back toward the middle of the body and down into the rectum.

The lining of the colon can sometimes have problems. It may have ulcers, or sores that bleed. It may have areas that are inflamed. And it may have small growths called polyps ["pahl'-ips"]. All of these can cause symptoms such as pain or diarrhea, or be signs of cancer. Most doctors recommend that people have a colonoscopy when they turn 50, and again every 5 to 10 years after that.

Before the Procedure

Before a colonoscopy, you'll need to empty your colon using what's known as "bowel prep." Your health care provider will give you detailed instructions how to use this special solution. You'll only be allowed to have clear liquids for a day before the test, and use a strong laxative the night before the test. You'll want to be near a bathroom after taking the laxative.

Your colon must be clean and free of all solid material for the test. It's possible that your health care provider may miss a problem if your colon is not clear. Make sure to follow all the instructions, or your health care provider may need to reschedule another test.

What to Expect

A colonoscopy takes thirty minutes to an hour. Before the procedure, you'll be given a sedative to make you relax or sleep. You'll lie down on your side on an exam table. Your health care provider may monitor your vital signs.

During your colonoscopy, your provider uses a special flexible tool called a colonoscope. The tip of the colonoscope is inserted into the anus. As it's moved into the rectum, air will flow into your colon to help it expand. If you're awake during the procedure, you may feel some cramping or have a feeling like you need to have a bowel movement. You may be able to watch the video screen and see the inside of your colon.

If you have polyps in your colon, your provider may use special tools inside the colonoscope to remove the polyp. A sample of tissue may also be taken to test in a lab. This is called a biopsy.

After the Procedure

After the test, you'll need to rest until the medication wears off. Then you'll need someone to drive you home. You might feel sleepy for a while after you get home. You may also have a lot of gas.

You'll get your test results within a week or two after the test. Your health care provider will talk with you about the results.

Things to Remember

Colonoscopy can help find the cause of symptoms such as bleeding or a change in bowel movements.

Colonoscopy can help find colon cancer before you have symptoms.

Small samples of tissue called biopsies can be taken during the test.

What We Have Learned

No prep is needed before a colonoscopy.
True or False?
The answer is false. You'll need to only drink clear liquids the day before, and use a strong laxative the night before to make sure you colon is clean for the test.

You'll be able to drive yourself home after the procedure.
True or False?
The answer is false. Because of the sedatives given before a colonoscopy, you'll need someone to drive you home after the test.