Colonoscopy and sigmoidoscopy are excellent screening exams for colorectal cancer (commonly referred to as “colon cancer”). But false information and a misplaced sense of modesty have scared some people away from these lifesaving tests. Here are some questions you might have and some answers for them:

• What is a colonoscopy? 
• What is a sigmoidoscopy 
• Will it hurt? 
• Who will do the exam? 
• Will I be in a private room? 
• How do I prepare? Will I need to miss work? 
• How will I feel afterward? Will I need someone to drive me home? 
• What if they find something? 
• Why are these tests so important?

What is a colonscopy?

A colonoscopy is an exam that allows a doctor to see and closely look at the inside of the entire colon for signs of cancer or polyps. Polyps are small growths that over time can become cancer. The doctor uses a slender, flexible, hollow, lighted tube about the thickness of a finger. This "colonoscope" is gently eased inside the colon and has a tiny video camera, which sends pictures to a TV screen. Small puffs of air are put in the colon to keep it open and allow the doctor to see clearly.

The exam itself takes 15 to 30 minutes. Patients are usually given medicine to help them relax, which often puts them to sleep during the procedure. Your doctor decides how often you need this test, usually once every 10 years, depending on your personal risk for colon cancer. It's important for people to talk with their doctor to understand their personal risk for getting colon cancer, the guidelines they should follow for testing, and whether they need to start being tested at age 50 or earlier.

What is a sigmoidoscopy?

During a sigmoidoscopy, a doctor closely inspects the lower parts of the colon, called the sigmoid colon and the descending colon, for signs of cancer or polyps. Polyps are small growths which can over time become cancer. The doctor uses a slender, flexible, hollow, lighted tube about the thickness of a finger. This "sigmoidoscope" is gently eased inside the colon and has a tiny video camera, which sends pictures to a TV screen. Small puffs of air are put in the colon to keep it open and allow the doctor to see clearly. The exam takes 15 to 20 minutes and the patient usually doesn't need medicine.

Will it hurt?

No, these two exams are not painful. For the most part, patients are given medicine to sleep through the colonoscopy, so they won't feel anything. Sigmoidoscopy doesn't require medicine to make the patient sleepy, so some patients find the air pressure to be uncomfortable. Air is pumped into the cleaned-out colon so it will hold its normal size and doctors can get the best pictures. While it may be slightly uncomfortable, it should not hurt.

Who will do the exam?

A colonoscopy is almost always done by a doctor, usually a gastroenterologist or a surgeon. Sigmoidoscopies are often done by primary care doctors (general practitioners, family doctors, and internal medicine doctors) in their office. Studies show that a well-trained clinical nurse specialist, nurse practitioner, or physician’s assistant can do sigmoidoscopies very effectively too.

Will I be in a private room?

Sigmoidoscopy is always done in a private room; no other patients are around. Doctors and nurse specialists are professional and very careful to respect the patient's privacy.

Colonoscopy is also performed in a private area; it may be done in a hospital outpatient department, a clinic, an ambulatory surgery center, or a doctor's office. The patient's privacy is a top concern.

How do I prepare? Will I need to miss work?

The preparation for the colonoscopy requires you to go the bathroom a lot! You follow a special diet the day before the exam and take very strong laxatives in the hours before the procedure. You may also need an enema to cleanse the colon. The key to getting good pictures is to have the colon cleaned out. Preparation for a sigmoidoscopy is much the same.

Because colonoscopy is usually done under sedation, people usually will miss a day of work. People should ask their doctors whether they'll need to miss work before a sigmoidoscopy. For either test you'll need to stay close to a bathroom. You might want to schedule the procedure for a Monday, so you can be at home the day before without taking a day off work.

How will I feel afterward? Will I need someone to drive me home?

Most people feel OK after a colonoscopy. They may feel a bit woozy. They'll be watched and given fluids after the procedure as they awaken from the anesthesia. They may have some gas, which could cause mild discomfort. Because of the sedation that is given for the test, most facilities ask that you bring someone to take you home.

After a sigmoidoscopy, you get up and walk out. There should be no problem driving yourself home, as long as you have not had any drugs to make you sleepy during the test.

What if they find something?

If a small polyp is found, your doctor will probably remove it because it could eventually become cancerous. If your doctor sees a large polyp, a tumor, or anything else abnormal, a biopsy will be done. For the biopsy, a small piece of tissue is taken out through the colonoscope or sigmoidoscope. It is sent to a lab to be checked under a microscope for cancerous or precancerous cells.

Why are these tests so important?

Removing polyps prevents colorectal cancer from ever starting. And cancers found in an early stage are more easily treated. Nine out of 10 people whose colon cancer is discovered early will be alive 5 years later. And many will live normal lifespans.

But too often people don't get these tests. Then the cancer can grow and spread unnoticed, like a silent invader. In many cases, by the time people have any symptoms the cancer is very advanced and very difficult to treat.

Revised 02/7/2008