MENUHomeNewsTopics A - Z
Accessibility|Contact|Privacy|Terms|Cookies

Colonoscopy: Information and What to Expect


  • Published: 2014-03-15 (Revised/Updated 2015-01-20) : Author: Disabled World : Contact: Disabled World
  • Synopsis: Information on Colonoscopy procedure to see inside the colon and rectum to detect inflamed tissue cancer ulcers and abnormal growths in the bowel.

Colonoscopy is a procedure used to see inside the colon and rectum. Colonoscopy can detect inflamed tissue, ulcers, and abnormal growths.

The endoscopic examination of the large bowel and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It can provide a visual diagnosis (e.g. ulceration, polyps) and grants the opportunity for biopsy or removal of suspected colorectal cancer lesions. A colonoscopy allows an examination of the entire colon. A sigmoidoscopy allows an examination of the distal portion (about 600 mm) of the colon. Medical societies recommend a screening colonoscopy every 10 years beginning at age 50 for adults without increased risk for colorectal cancer.

Information in this Article:

What is Colonoscopy

Colonoscopy is a procedure used to see inside the colon and rectum. Colonoscopy can detect inflamed tissue, ulcers, and abnormal growths. The procedure is used to look for early signs of colorectal cancer and can help doctors diagnose unexplained changes in bowel habits, abdominal pain, bleeding from the anus, and weight loss.

Diagram with inset showing overview of colonoscopy procedureAbout This Image: Diagram with inset showing overview of colonoscopy procedureWhat are the colon and rectum

The colon and rectum are the two main parts of the large intestine. Although the colon is only one part of the large intestine, because most of the large intestine consists of colon, the two terms are often used interchangeably. The large intestine is also sometimes called the large bowel.

Drawing of the digestive tract with labels pointing to the liver, stomach, small intestine, colon, rectum, and anus. The colon is shaded. The colon and rectum are the two main parts of the large intestine.

Digestive waste enters the colon from the small intestine as a semisolid. As waste moves toward the anus, the colon removes moisture and forms stool. The rectum is about 6 inches long and connects the colon to the anus. Stool leaves the body through the anus. Muscles and nerves in the rectum and anus control bowel movements.

How to Prepare for Colonoscopy

Good bowel cleansing is essential for high-quality colonoscopy. The success of a colonoscopy is closely linked to good bowel preparation, with poor bowel prep often resulting in missed precancerous lesions, according to new consensus guidelines released by the U.S. Multi-Society Task force on Colorectal Cancer. Additionally, poor bowel cleansing can result in increased costs related to early repeat procedures. Up to 20 to 25 percent of all colonoscopies are reported to have an inadequate bowel preparation.

The doctor usually provides written instructions about how to prepare for colonoscopy. The process is called a bowel prep. Generally, all solids must be emptied from the gastrointestinal tract by following a clear liquid diet for 1 to 3 days before the procedure. Patients should not drink beverages containing red or purple dye. Acceptable liquids include

A laxative or an enema may be required the night before colonoscopy. A laxative is medicine that loosens stool and increases bowel movements. Laxatives are usually swallowed in pill form or as a powder dissolved in water. An enema is performed by flushing water, or sometimes a mild soap solution, into the anus using a special wash bottle.

Patients should inform the doctor of all medical conditions and any medications, vitamins, or supplements taken regularly, including

Driving is not permitted for 12 hours after colonoscopy to allow the sedative time to wear off. Before the appointment, patients should make plans for a ride home.

How is colonoscopy performed

Examination of the Large Intestine

During colonoscopy, patients lie on their left side on an examination table. In most cases, a light sedative, and possibly pain medication, helps keep patients relaxed. Deeper sedation may be required in some cases. The doctor and medical staff monitor vital signs and attempt to make patients as comfortable as possible.

During colonoscopy, patients lie on their left side on an examination table.

The doctor inserts a long, flexible, lighted tube called a Colonoscopy, or scope, into the anus and slowly guides it through the rectum and into the colon. The scope inflates the large intestine with carbon dioxide gas to give the doctor a better view. A small camera mounted on the scope transmits a video image from inside the large intestine to a computer screen, allowing the doctor to carefully examine the intestinal lining. The doctor may ask the patient to move periodically so the scope can be adjusted for better viewing.

Once the scope has reached the opening to the small intestine, it is slowly withdrawn and the lining of the large intestine is carefully examined again. Bleeding and puncture of the large intestine are possible but uncommon complications of colonoscopy.

Removal of Polyps and Biopsy

A doctor can remove growths, called polyps, during colonoscopy and later test them in a laboratory for signs of cancer. Polyps are common in adults and are usually harmless. However, most colorectal cancer begins as a polyp, so removing polyps early is an effective way to prevent cancer.

The doctor can also take samples from abnormal-looking tissues during colonoscopy. The procedure, called a biopsy, allows the doctor to later look at the tissue with a microscope for signs of disease.

The doctor removes polyps and takes biopsy tissue using tiny tools passed through the scope. If bleeding occurs, the doctor can usually stop it with an electrical probe or special medications passed through the scope. Tissue removal and the treatments to stop bleeding are usually painless. Recovery

Colonoscopy usually takes 30 to 60 minutes. Cramping or bloating may occur during the first hour after the procedure. The sedative takes time to completely wear off. Patients may need to remain at the clinic for 1 to 2 hours after the procedure. Full recovery is expected by the next day. Discharge instructions should be carefully read and followed.

Patients who develop any of these rare side effects should contact their doctor immediately:

At what age should routine colonoscopy begin

Routine colonoscopy to look for early signs of cancer should begin at age 50 for most people, earlier if there is a family history of colorectal cancer, a personal history of inflammatory bowel disease, or other risk factors. The doctor can advise patients about how often to get a colonoscopy.

Points to Remember

Hope through Research

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) conducts and supports basic and clinical research into many digestive disorders. The NIDDK is working to improve colonoscopy by developing new tools, including tools that improve the ability to detect all colon polyps and to identify people at increased risk of colorectal cancer. Such tools will help train doctors to perform colonoscopy, improve safety, and make the procedure more comfortable for patients.

Submit disability news, coming events, as well as assistive technology product news and reviews.


Loan Information for low income singles, families, seniors and disabled. Includes home, vehicle and personal loans.


Famous People with Disabilities - Well known people with disabilities and conditions who contributed to society.


List of awareness ribbon colors and their meaning. Also see our calendar of awareness dates.


Blood Pressure Chart - What should your blood pressure be, and information on blood group types/compatibility.






Disclaimer: This site does not employ and is not overseen by medical professionals. Content on Disabled World is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition. See our Terms of Service for more information.

Reporting Errors: Disabled World is an independent website, your assistance in reporting outdated or inaccurate information is appreciated. If you find an error please let us know.

© 2004 - 2018 Disabled World™