Colonoscopy is a diagnostic procedure performed to examine the inner lining of the colon, also known as the large intestine, and the rectum. The colonoscopy procedure can aid in determining the cause of changes in bowel activity, abdominal pain and rectal bleeding, as well as detect early possible signs of cancer, such as colon polyps.
A colonoscopy procedure is performed with a tool called a colonoscope, which has a small camera attached to a flexible tube that can reach the entire length of the colon. During a colonoscopy, tissue samples may be collected for a biopsy, and abnormal growths may be removed.
Reasons for a Colonoscopy
Colonoscopies are recommended as an option for people who are at increased risk of developing cancer of the colon or rectum, known as colorectal cancer or CRC. This type of cancer is much easier to treat when detected early. Risk factors that may contribute to the development of colorectal cancer include:
- Personal or family history of colorectal polyps
- Age, especially if the patient is 50 or older
- Personal or family history of inflammatory bowel disease, or IBD
- Poor diet
- Family history of colon or rectal cancer
- Heavy alcohol use
- Lack of exercise or physical activity
Preparing for a Colonoscopy
Prior to the colonoscopy, patients will be given a set of written instructions to follow. A clear liquid diet must be adhered to for about 1 to 2 days before the procedure. Some clear liquids that may be consumed during this time period include water, strained fruit juices, fat-free broth, sports drinks, gelatin and clear teas or coffees.
Depending on the instructions provided, a laxative or enema may be required. Patients will need to drink a special bowel cleansing solution the day before the procedure. Most medications can still be taken although some, such as aspirin or blood thinners, may require special instructions.
The Colonoscopy Procedure
A colonoscopy is generally performed as an outpatient procedure. Before the colonoscopy begins, a light sedative will be administered through an intravenous, or IV, line to make the patient comfortable. Vital signs will be closely monitored throughout the procedure. The patient is positioned to lie on his or her left side as the colonoscope is gently inserted into the anus. The scope will then be carefully moved into the lower portion of the large intestine and guided upward toward the lowest portion of the small intestine.
The scope will then be slowly withdrawn from the colon, and the lining of the colon is carefully examined by the physician. If necessary, the removal of polyps, or growths, for biopsy may also be conducted during the procedure. The colonoscopy procedure usually takes between 20-40 minutes to perform.
Recovery from a Colonoscopy
After the colonoscopy procedure, the patient will be kept for observation for up to 2 hours, until the sedative used for the procedure wears off. Reflexes and judgment may be impaired and driving is not permitted for 24 hours after the procedure. Some people may experience pressure, bloating and cramping in the abdomen after the procedure, but these side effects are temporary and well tolerated.
Complications of a Colonoscopy
A colonoscopy is considered a safe and effective procedure, with very little risk of complications. If complications do occur, they may include:
- Abdominal pain
- Mild abdominal cramping
- Bleeding from the biopsy site
- Perforation of the bowel wall
- Reaction to the medication used in the IV