Colonoscopy is a safe, effective method of examining the full lining of the colon and rectum, using a long, flexible, tubular instrument. It is used to diagnose colon and rectum problems and to perform biopsies and remove colon polyps. Most colonoscopies are done on an outpatient basis with minimal inconvenience and discomfort.
Colonoscopy is routinely recommended to adults 50 years of age or older as part of a colorectal cancer screening program. Patients with a family history of colon or rectal cancer may have their colonoscopy at age 40. Your physician may also recommend a colonoscopy exam if you have change in bowel habit or bleeding, indicating a possible problem in the colon or rectum.
A colonoscopy may be necessary to:
- Check unexplained abdominal symptoms
- Check inflammatory bowel disease (colitis)
- Verify findings of polyps or tumours located with a barium enema exam
- Examine patients who test positive for blood in the stool
- Monitor patients with a personal or family history of colon polyps or cancer.
The bowel must first be thoroughly cleared of all residue before a colonoscopy. This is done one to two days before the exam with a preparation prescribed by your physician.
Many patients receive intravenous sedation, or “twilight sleep” for this procedure. The colonoscope is inserted into the rectum and is advanced to the portion of the colon where the small intestine joins the colon. During a complete examination of the bowel, your physician will remove polyps or take biopsies as necessary.
The entire procedure usually takes less than an hour. Following the colonoscopy, there may be slight discomfort, which quickly improves with the expelling of gas. Most patients can resume their regular diet and activities the same day.
Colonoscopy is more accurate than an x-ray exam of the colon to detect polyps or early cancer. With colonoscopy, it is now possible to detect and remove most polyps without abdominal surgery. Removing polyps is an important step in the prevention of colon cancer.
Colonoscopy is a very safe procedure with complications occurring in less than 1% of patients. These risks include bleeding, a tear in the intestine, risks of anaesthesia and failure to detect a polyp.