What is a Colonoscopy?

Colonoscopy (lower endoscopy) is a diagnostic procedure that allows the physician to examine the entire length of the large intestine. Colonoscopy can assist in identifying problems with the colon, such as early signs of cancer, polyps, inflammation, ulcers, and bleeding. 

Colorectal cancer is the 3rd most common cause of cancer-related deaths in men and women in the United States. A Colonoscopy Could Save Your Life.  Schedule Your's Today. 

Contact Information

Kent Hospital
455 Toll Gate Road
Warwick, RI 02886
P: (401) 593-1581

Colorectal Cancer Screening

Screenings can detect colorectal cancer when it can be treated. For individuals at normal risk, screening tests should begin at age 45.

Learn More About Colorectal Cancer Screening

The Colonoscopy Procedure

During the procedure, a thin, flexible, lighted tube, called a colonoscope, is placed into the rectum and colon. In addition to allowing visualization of the internal colon, the colonoscope enables the physician to irrigate, suction, inject air, and access the intestine with surgical instruments. During a colonoscopy, the physician may remove tissue and/or polyps for further examination and possibly treat any problems that are discovered.

Other related procedures that may be used to assess problems of the colon include abdominal x-ray, computed tomography (CT scan) of the abdomen, abdominal ultrasound, barium enema, and sigmoidoscopy. 

  • Preparing for a Colonoscopy
  • What To Expect During the Colonoscopy
  • What To Expect After the Colonoscopy

Before a colonoscopy, you will need to “prep” or clean out your colon so the doctor can see with the colonoscope. Residue left in the colon may obscure the view of your colon and rectum.

Your doctor will give you special instructions which will include:

  • Special Diet: Following a special diet the day before the exam. Typically you will not be able to eat solid food the day before the exam. Drinks may be limited to clear liquids — plain water, tea and coffee without milk or cream, broth, and carbonated beverages. Avoid red liquids, which can be confused with blood during the colonoscopy. You may not be able to eat or drink anything after midnight the night before the exam.
  • Laxative: Your doctor will recommend taking a laxative prior to your colonoscopy to clean out your colon.
  • Adjust Your Medications: Your doctor may ask you to adjust your medications the day before and the day of the colonoscopy-especially in patients with diabetes, high blood pressure, heart problems, and those on blood thinners. Please talk to your doctor about your medications prior to your colonoscopy.

During a colonoscopy, you'll wear a gown. Sedation is given by the anesthesia team to keep you comfortable and you are monitored throughout the procedure

You'll begin the exam lying on your side on the exam table, usually with your knees drawn toward your chest. The doctor will insert a colonoscope into your rectum.

The scope — which is long enough to reach the entire length of your colon — contains a light and a tube (channel) that allows the doctor to pump air or carbon dioxide into your colon. The air or carbon dioxide inflates the colon, which provides a better view of the lining of the colon.

The colonoscope also contains a tiny video camera at its tip. The camera sends images to an external monitor so that the doctor can study the inside of your colon.

The doctor can also insert instruments through the channel to take tissue samples (biopsies) or remove polyps or other areas of abnormal tissue.

A colonoscopy typically takes about 30 to 60 minutes.

After the exam, it takes a short time to recover from the anesthetic. You'll need someone to take you home because it can take up to a day for the full effects of the sedative to wear off. Don't drive or make important decisions or go back to work for the rest of the day.

If your doctor removed a polyp during your colonoscopy, you may be advised to eat a special diet temporarily.

You may feel bloated or pass gas for a few hours after the exam, as you clear the air from your colon. Walking may help relieve any discomfort.

You may also notice a small amount of blood with your first bowel movement after the exam. Usually, this isn't cause for alarm. Consult your doctor if you continue to pass blood or blood clots or if you have persistent abdominal pain or a fever. While unlikely, this may occur immediately or in the first few days after the procedure, but may be delayed for up to one to two weeks.

Colonoscopy Resources

Melissa M. Murphy, MD, Executive Chief of Surgery

The question, "why should I get a colonoscopy" is a question I am frequently asked as a colon and rectal surgeon, says Melissa M. Murphy, MD, Executive Chief of Surgery, Care New England Health System...

Care New England

At the height of the COVID-19 pandemic, people put off routine health screenings. However, with over half of the country fully vaccinated against COVID-19, it is now much safer to come in for routine ...

Women & Infants Hospital

Colorectal cancer disproportionately affects the Black community. Colorectal cancer rates among African-Americans are the highest of any racial/ethnic group in the U.S., making African-Americans appro...

Test Results

Negative result

A colonoscopy is considered negative if the doctor doesn't find any abnormalities in the colon.Lovers on the bench-2

Your doctor may recommend that you have another colonoscopy:

  • In 10 years, if you're at average risk of colon cancer — you have no colon cancer risk factors other than age
  • In 3-5 years, if you have a history of polyps in previous colonoscopy procedures or strong family history.
  • In 1-2 years, if there was a residual stool in the colon that prevented complete examination of your colon

Positive result

A colonoscopy is considered positive if the doctor finds any polyps or abnormal tissue in the colon.

Most polyps aren't cancerous, but some can be precancerous. Polyps removed during colonoscopy are sent to a laboratory for analysis to determine whether they are cancerous, precancerous or noncancerous.

It takes on average 5-7 days for your doctor to receive the pathology report on the polyps/specimens removed during the colonoscopy.

Depending on the size and number of polyps, you may need to follow a more rigorous surveillance schedule in the future to look for more polyps.

If your doctor finds one or two polyps less than 0.4 inch (1 centimeter) in diameter, he or she may recommend a repeat colonoscopy in five years, depending on your other risk factors for colon cancer.

Your doctor will recommend another colonoscopy sooner if you have:

  • More than two polyps
  • A large polyp — larger than 0.4 inch (1 centimeter)
  • Polyps and also residual stool in the colon that prevents complete examination of the colon
  • Polyps with certain cell characteristics that indicate a higher risk of future cancer
  • Cancerous polyps

If you have a polyp or other abnormal tissue that couldn't be removed during the colonoscopy, your doctor may recommend a repeat exam with a gastroenterologist who has special expertise in removing large polyps, or surgery.


Colonoscopy FAQs

How Does a Colonoscopy Reduce Your Risk of Colon Cancer?

Colorectal cancer is the third most common cause of cancer in men and women in the US and the second leading cause of cancer death in the US when men and women are combined. Colorectal cancer is one of the most preventable cancers in those who undergo screening. So why should you have a colonoscopy?

  • Colon cancer can happen to anyone
Most people who get colon cancer are over age 50. However, in the last decade, the rate of colon cancer in younger adults less than age 50 is on the rise. Colon cancer can be found in otherwise healthy people with no family history of the disease.
  • Colonoscopies prevent colon cancer
Colon cancer develops when small growths called polyps develop on the lining of the colon. Over time these polyps can grow and develop into cancer. During a colonoscopy the doctor can identify these polyps and remove them and decrease the risk of colon cancer.
You may have no symptoms
Many patients with polyps and early cancer may have no symptoms. The idea is to remove the polyps before they develop into a cancer which may cause symptoms.
  • Colonoscopies are not as bad as you may think
People are often nervous about the “prep” for a colonoscopy. The bowel prep has improved and the cleansing formulas are more efficient today. Sedation is given during the procedure by an anesthesiologist to keep you comfortable. Most people find they don’t remember the procedure afterward.
  • Colonoscopies are accurate
Doctors call colonoscopies the “gold standard” for colon cancer. More than 95% of cancer cells and precancerous polyps in the colon are identified on colonoscopy.
  • Colonoscopies are safe
Colonoscopies are very safe when performed by specialists (gastroenterologists, colorectal surgeons). There is a very small risk of bleeding or a perforation(small hole in the bowel) but the risk is less than 1 in 1000 patients. In contrast, approximately 1 in 18 people will develop cancer in their lifetime.
Why Should Someone Have a Colonoscopy?
Your doctor may recommend a colonoscopy to:
  • Investigate intestinal signs and symptoms including abdominal pain, rectal bleeding, chronic constipation, diarrhea, and other intestinal problems.
  • Screen for colon cancer
  • Look for polyps if you have a personal history of polyps to reduce your risk of colon cancer
When Should Someone Have a Colonoscopy?
The American Cancer Society and the U.S. Preventative Services Task Force recommend that screening for colorectal cancer for average-risk people should start at age 45. If you have a family history of colon cancer or polyps in your family you may need to be screened earlier than age 45.