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Colonoscopy

A test to look into the rectum and colon that uses a long, flexible, narrow tube with a light and tiny camera on the end. The tube is called a colonoscope.

PubMed Health Glossary
(Source: NIH - National Institute of Diabetes and Digestive and Kidney Diseases)

About Colonoscopy

The colonoscopy works by searching for polyps and signs of early cancer in your colon. Polyps are small growths that may eventually turn into cancer. Polyps can be removed during a colonoscopy. Cancer can be treated successfully if detected early.

It takes a commitment of one to two full days to have a colonoscopy, which includes time for preparation and recovery. Specialists (often gastroenterologists) do this procedure regularly.

The cleaner your colon is, the easier you'll make it for your doctor to find polyps. This means you'll need to completely empty your bowel before your colonoscopy.

Most people are asked to drink a prescribed liquid substance the day before the procedure that causes frequent trips to the bathroom with diarrhea. Your doctor will give you specific instructions. You may need to adjust your other medications.

Because you will be sedated for the colonoscopy, you'll need to arrange for a ride home after the procedure....Read more about Colonoscopy
NIH - National Cancer Institute

What works? Research summarized

Evidence reviews

[Transparent Cap Colonoscopy versus Standard Colonoscopy to Improve Caecal Intubation]

Fourteen randomised controlled trials were included in the review comparing Colonoscopy with the Transparent Cap with Standard Colonoscopy in the investigation of gastrointestinal tract conditions. The findings of our work suggest that there is improvement in time to caecal intubation (which indicates that the colonoscopy is complete) when using the transparent cap compared with standard colonoscopy, although this is not statistically significant. We conclude that further research is required to assess the clinical significance of this result, especially considering that there have been no adverse events noted.]

Narrow band imaging colonoscopy is not better than white light colonoscopy in detecting the patients with colorectal polyps.

Cancer of the large bowel is the third most common cancer worldwide. It has been suggested that colorectal polyps are precursors of colorectal cancer. Consequently, early detection and removal of colorectal polyps is important in secondary prevention of colorectal cancer. A number of randomised trials comparing narrow band imaging colonoscopy (a high resolution endoscopic technique that enhances the fine structure of the mucosal surface) with white light colonoscopy for detection of colorectal polyps reported variable results.

The use of Nitrous Oxide gas during Colonoscopy procedures

Colonoscopy is now the main investigation for large bowel illnesses, including cancer, but it can be an uncomfortable or painful procedure. To help reduce the pain/discomfort, endoscopists use narcotics or hypnotics with or without other analgesics, but this, in turn, comes with risks on the heart as well as on breathing. This review found that Nitrous Oxide gas works as good sedation, it leads to faster recover after the procedure and a short stay at the endoscopy unit, with little risk to breathing or the heart.

See all (242)

Summaries for consumers

[Transparent Cap Colonoscopy versus Standard Colonoscopy to Improve Caecal Intubation]

Fourteen randomised controlled trials were included in the review comparing Colonoscopy with the Transparent Cap with Standard Colonoscopy in the investigation of gastrointestinal tract conditions. The findings of our work suggest that there is improvement in time to caecal intubation (which indicates that the colonoscopy is complete) when using the transparent cap compared with standard colonoscopy, although this is not statistically significant. We conclude that further research is required to assess the clinical significance of this result, especially considering that there have been no adverse events noted.]

Narrow band imaging colonoscopy is not better than white light colonoscopy in detecting the patients with colorectal polyps.

Cancer of the large bowel is the third most common cancer worldwide. It has been suggested that colorectal polyps are precursors of colorectal cancer. Consequently, early detection and removal of colorectal polyps is important in secondary prevention of colorectal cancer. A number of randomised trials comparing narrow band imaging colonoscopy (a high resolution endoscopic technique that enhances the fine structure of the mucosal surface) with white light colonoscopy for detection of colorectal polyps reported variable results.

The use of Nitrous Oxide gas during Colonoscopy procedures

Colonoscopy is now the main investigation for large bowel illnesses, including cancer, but it can be an uncomfortable or painful procedure. To help reduce the pain/discomfort, endoscopists use narcotics or hypnotics with or without other analgesics, but this, in turn, comes with risks on the heart as well as on breathing. This review found that Nitrous Oxide gas works as good sedation, it leads to faster recover after the procedure and a short stay at the endoscopy unit, with little risk to breathing or the heart.

See all (36)

Terms to know

Colon (Bowel)
The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus.
Colon Polyp
An abnormal growth of tissue in the lining of the bowel. Polyps are a risk factor for colon cancer.
Colorectal Cancer (Colorectal Carcinoma)
Cancer that develops in the colon (the longest part of the large intestine) and/or the rectum (the last several inches of the large intestine before the anus).
Familial Adenomatous Polyposis (FAP)
An inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. It increases the risk of colorectal cancer. Also called familial polyposis and FAP.
Gastroenterologist
A doctor who has special training in diagnosing and treating disorders of the digestive system.
Rectum
The last several inches of the large intestine closest to the anus.

More about Colonoscopy

Photo of an adult

Also called: Endoscopy of the colon

See Also: Sigmoidoscopy

Other terms to know: See all 6
Colon (Bowel), Colon Polyp, Colorectal Cancer (Colorectal Carcinoma)

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