The term "colonoscopy" means looking inside the colon. It is a procedure performed by a gastroenterologist, a well-trained subspecialist.
Colonoscopy is a procedure used to view large intestine (colon and rectum) using an instrument called colonoscope (a flexible tube with a small camera and lens attached). The procedure can detect inflamed tissue, ulcers, and abnormal growths. It is used to diagnose early signs of colorectal cancer, bowel disorders, abdominal pain, muscle spasms, inflamed tissue, ulcers, anal bleeding, and non-dietary weight loss.
Indications for colonoscopy are:
- Rectal bleeding
- Iron deficiency anaemia
- Abdominal pain and alteration in bowel habit
- The presence of colorectal cancer risk factors
- Clarification of barium enema findings
- Positive Faecal occult test
- Indication for repeat colonoscopy
- Patients with previous bowel polyps or cancer
- Surveillance of inflammatory bowel disease
- Patients with a family history of bowel cancer or polyps in first degree relatives
The procedure is done under general anaesthesia. The colonoscope is inserted into the rectum, which gently moves up through the colon until it reaches the cecum (junction of small and large intestine). Colonoscopy provides an instant diagnosis of many conditions of the colon and is more sensitive than X-ray.
The colonoscope is then withdrawn very slowly as the camera shows pictures of the colon and rectum onto a large screen. Polyps or growths can also be removed by colonoscopy, which can be sent later for detection of cancer.
Instructions for colonoscopy
Your physician may provide you written instructions and also will be communicate verbally on how to get prepared for the colonoscopy procedure. The process is called bowel prep.
Gastrointestinal (GI) tract should be devoid of solid food; a strict liquid diet should be followed for 1 to 3 days before the procedure. Patients should not drink beverages containing red or purple dye. Liquids that can be taken before surgery include fruit juices, plain coffee, tea, and water
Certain medications such as aspirin, ibuprofen, naproxen or other blood thinning medications, iron containing preparation should be stopped before the test. Iron medications produce a dark black stool, and this makes the view inside the bowel less clear.
A laxative or an enema may be required the night before a colonoscopy. Laxative is medicine that loosens stool and increases bowel movements. Laxatives are usually swallowed in pill form or as a powder dissolved in water.
Driving is not permitted for 12 hours after colonoscopy.
Other features of colonoscopy:
- Colonoscopy is more precise than an X-ray. This procedure also allows other instruments to be passed through the colonoscope. These may be used, for example, to painlessly remove a suspicious-looking growth or to take a biopsy-a small piece for further analysis. In this way, colonoscopy may help to avoid surgery or to better define what type of surgery may need to be done.
- Colonoscopy is a safe and effective way to evaluate problems such as blood loss, pain, and changes in bowel habits such as chronic diarrhoea or abnormalities that may have first been detected by other tests. Colonoscopy can also identify and treat active bleeding from the bowel.
- Colonoscopy is also an important way to check for colon cancer and to treat colon polyps – abnormal growths on the inside lining of the intestine. Polyps vary in size and shape and, while most are not cancerous, some may turn into cancer. However, it is not possible to tell just by looking at a polyp if it is malignant or potentially malignant. This is why colonoscopy is often used to remove polyps, a technique called a polypectomy.