What is a colonoscopy?

Dr. Walter J. Coyle, MD on behalf of Scripps Health

Gastroenterologist

A colonoscopy is used to detect cancer or precancerous polyps in the colon. It can also help to diagnose other gastrointestinal issues. During a colonoscopy, your doctor will use a thin tube with a camera and light at the end to take photos of your upper and lower colon. Most people should begin getting diagnostic colonoscopies at age 50. If you have a family history of colorectal cancer, however, your physician may recommend that you begin regular screenings at a younger age.

Univ. of Nev. School of Medicine, Family Medicine

A colonoscopy is a screening test for patients over the age of fifty, or earlier for those with a family history of colon cancer. During a colonoscopy, patients are usually sedated while a small fiber optic camera mounted on a flexible tube is passed through the anus. Physicians who perform this exam are called gastroenterologists. Once the tube has been inserted, the physician will scan the colon as well as a part of the small intestine. Any abnormalities are noted, and oftentimes physicians will also take biopsies of any unusual tissues that they see. Colonoscopies are one of the most effective ways of screening for colon cancer.

Atlanta Gastroenterology Associates

The colon, which is shaped like a very large question mark with many twists and turns, begins in the right lower abdomen and ends in the rectum. A colonoscopy is a safe, effective method of visually examining the colon using a very narrow lighted, flexible fiber optic tube called a colonoscope. At the end of the tube is a miniature camera with a wide-angle lens that helps your doctor examine the lining of your digestive tract on a video monitor. More accurate than a barium enema X-ray and much simpler than exploratory abdominal surgery, colonoscopy is safe and generally well tolerated by patients.

Columbia University Department of Surgery

Colonoscopy enables your physician to examine the lining of the colon for abnormalities. While the patient is under mild sedation, the physician inserts a flexible fiber-optic instrument called a colonoscope into the rectum and advances it through the colon (large bowel). Cancer can occur anywhere from the end of the colon (rectum) to the beginning of the colon, which is called the cecum. The colonoscope examines this entire area. Polyps and even small tumors can be removed painlessly at the time of a colonoscopy, so it is really a "therapeutic," not just a "diagnostic," test.

Dr. Grace H. Elta, MD on behalf of American Society for Gastrointestinal Endoscopy

Gastroenterologist

Colonoscopy is a common and very safe procedure that examines the lining of the lower intestinal tract called the colon or large intestine or bowel. A doctor specially trained in the procedure uses a flexible tube that has a light and miniature TV camera on the tip. This instrument, often referred to as the "scope," is placed in the rectum and advanced through the colon. It is connected to a television monitor that the doctor watches while performing the test. Various miniaturized tools can be inserted through the scope to help the doctor obtain biopsies (samples) of the colon and to perform a wide range of maneuvers to help diagnose or treat a condition. When used as a colon cancer prevention method, colonoscopy can find potentially precancerous polyps and remove them before they turn into cancer.

Carla Rohloff on behalf of Aurora Health Care

Oncology Nursing Specialist

A colonoscopy is a procedure where your doctor can closely check the lining of the entire colon (large bowel). During a colonoscopy, your doctor inserts a tube through your rectum into your colon. A camera attached to the tube allows your doctor to view the inside of your colon and check for abnormailities. Polyps can be removed and biopsies taken to rule out cancer.

NorthShore University HealthSystem

A colonoscopy is a procedure performed with a flexible tube that is inserted into the anus that allows for the visualization of the entire colon. Prior to a colonoscopy, the bowel is purged and it is typical for patients to receive sedation. The advantage of a colonoscopy is its accuracy and ability to remove polyps which decreases future risk of colorectal cancer.

Intermountain Registered Dietitians on behalf of Intermountain Healthcare

Nutrition & Dietetics Specialist

A colonoscopy is a procedure that uses a device called a colonoscope to look at the inside of your rectum and colon. (The colon (large intestine) is the last part of the digestive system. It’s a hollow tube, 4 to 6 feet long, starting at the small intestine and ending at the rectum.) The colonoscope is a long, flexible tube with a tiny video camera at the end. The camera sends images to a monitor, allowing your doctor to see a variety of problems.
Colonoscopy is the best test for detecting pre-cancerous polyps and cancer. The doctor can often remove polyps, perform biopsies, and treat problems during theprocedure itself.

Dr. Daniel M. Labow, MD on behalf of The Mount Sinai Health System

Surgical Oncologist

This is a test where a flexible tube the diameter of large pencil is inserted into the rectum, and the entire colon is examined through this telescope. It involves cleaning out the colon the day before to allow for a good view of the entire colon.

Brigham and Women's Hospital

Colonoscopy 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, inflamed tissue, ulcers, and bleeding. Colonoscopy is also used to screen for colorectal cancer, the second leading cause of cancer deaths in the US.

An endoscope—a long, flexible, lighted tube (also called a colonoscope)—is inserted through the rectum into the colon. In addition to allowing visualization of the internal colon, the colonoscope enables the physician to irrigate, suction, inject air, and access the bowel with surgical instruments. During a colonoscopy, the physician may remove tissue for further examination and possibly treat any problems that are discovered.

A colonoscopy may be used to examine colon polyps, tumors, ulceration, inflammation, diverticula (pouches), strictures (narrowing), and foreign objects within the colon. It may also be used to determine the cause of unexplained chronic diarrhea or gastrointestinal bleeding or to evaluate the colon after cancer treatment.

Colonoscopy may be indicated when the results of a barium enema and/or sigmoidoscopy warrant further examination of the colon.

American Society for Gastrointestinal Endoscopy

Colonoscopy lets your doctor examine the lining of your large intestine (colon) for abnormalities by inserting a thin flexible tube, as thick as your finger, into your anus and slowly advancing it into the rectum and colon. This instrument, called a colonoscope, has its own lens and light source and it allows your doctor to view images on a video monitor.

Riverside Cancer Care Center

A colonoscope is a thin, tube-like instrument used to examine the inside of the colon. A colonoscope has a light and a lens for viewing and may have a tool to remove tissue.

This answer is based on source information from the National Cancer Institute.

Dr. Vincent T DeVita Jr

Oncologist

Colonoscopy is a test in which the doctor looks at the entire length of the colon and rectum with a colonoscope, which is basically a longer version of a sigmoidoscope. It is inserted through the rectum into the colon. The colonoscope has a video camera on the end that is connected to a display monitor so the doctor can see and closely examine the inside of the colon. Special instruments can be passed through the colonoscope to remove (biopsy) any suspicious looking areas such as polyps, if needed. Colonoscopy may be done in a hospital outpatient department, in a clinic, or in a doctor's office.

NewYork-Presbyterian Hospital

A colonoscopy is a procedure that allows the physician to view the entire length of the large intestine, and can often help identify abnormal growths (polyps), inflamed tissue, ulcers, and bleeding. It involves inserting a colonoscope -- a thin, flexible tube with a light and camera at the end—through the rectum up into the colon. The colonoscope allows the physician to see the lining of the colon, remove tissue for further examination, and possibly treat some problems that are discovered. Patients are sedated during this procedure, which typically takes 20-30 minutes. Preparation for a colonoscopy may include a liquid diet several days prior to the procedure, a laxative the night before, and an enema the day of the procedure.

Sigma Nursing

A colonoscopy is a routine exam to diagnose rectal cancer and colon cancer. During a colonoscopy, your doctor inserts a tube through your rectum and into your colon. A camera attached to the tube allows your doctor to view the inside of your colon and check for abnormalities. Polyps and early stages of cancer can be removed during a colonoscopy.

Henrico Doctors' Hospital - HCA Virginia

A colonoscopy is recommended for people at risk for colorectal cancer every 10 years. Doctors use a flexible, lighted tube (colonoscope) to look at the interior walls of the rectum and the entire colon. During this procedure, samples of tissue may be collected for closer examination, or polyps may be removed.

Scripps Health

Colonoscopy is considered the “gold standard” screening for colon cancer and also enables doctors to remove any suspicious growths or tissue during the procedure. Colonoscopy is generally recommended every 10 years.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.