A colonoscopy is one of those procedures no one likes to talk about, but which is critically important to your continued healthy life as you age. Screening for colon cancer and rectal cancer is an important function of colonoscopy. Cancer of the large bowel, also called colorectal cancer, usually develops from a benign precursor, a polyp. A polyp is a mushroom-like growth on the inside wall of the colon or rectum. Polyps grow slowly over many years; some become cancerous, others do not.
Removing colon polyps will reduce the chances of developing colorectal cancer by 87 to 93 percent. In order to achieve this level of success in cancer prevention, colonoscopy should be performed in healthy individuals before the symptoms of bowel cancer are present. Colonoscopy is also recommended for a number of other reasons. Some of the more common symptoms include:
- Rectal bleeding
- Iron-deficiency anemia
- Recent change of bowel habits
- Abdominal pain
- Persistent diarrhea
Individuals with an extended history of ulcerative colitis or Crohn's disease, a personal history of colon polyps or cancer, or a family history of either polyps or cancer of the colon require periodic examination of the colon.
Routine colonoscopy to look for early signs of cancer should begin at age 50 for most people—and earlier if there is a family history of colorectal cancer, a personal history of inflammatory bowel disease, or other risk factors.
As your specialist, I will advise you how often you should have a colonoscopy exam, depending on your health history and any symptoms. The exams can be mildly uncomfortable, and we will provide appropriate medication to ensure you are not in distress during the exam.
When I am examining your large intestine, I insert a thin flexible tube into your rectum and advance through the entire five to six-foot length of the colon. The examination can detect an abnormality present within the inner lining of the colon, such as a tumor or polyp, or an area of inflammation or infection. To ensure that I am able to successfully perform the colonoscopy, you must do your part as well – and that means adequately preparing for the procedure.
To provide me with the best view of your colon as possible, you must adhere to a clear liquid diet for one to three days before your exam. You must clear your gastrointestinal tract of all solids. To ensure a clear view, you must not drink beverages containing red or purple dye for several days before the exam.
During a colonoscopy, you will lay on your left side on an examination table. In most cases, a light sedative, and possibly pain medication, will keep you relaxed. Deeper sedation may be required in some cases. The medical staff and I monitor vital signs and attempt to make you as comfortable as possible.
I will insert a long, flexible, lighted tube called a colonoscope, or scope, into the anus and slowly guide it through the rectum and into the colon. The scope is about the width of a little finger.
The scope inflates the large intestine with carbon dioxide to give me a better view. A tiny camera mounted on the scope transmits video from inside the large intestine to a computer screen, allowing me to carefully examine your intestinal lining. I can also remove any suspicious-looking growth for biopsy.
I may ask you 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 – and very rare.
Colonoscopy usually takes 30 to 60 minutes. Cramping or bloating may occur during the first hour after the procedure. The sedative takes the time to completely wear off. Patients may need to remain at the hospital for one to two hours after the procedure. Be sure to fully and carefully read your discharge instructions and follow the notes I provide you.
You should not drive for 12 to 24 hours after colonoscopy, to allow the sedatives to completely wear off.
If you develop any of these side effects – which are rare – contact me immediately:
- Severe abdominal pain
- Bloody bowel movements
When you schedule your test, I will provide you with instructions for the test and a preparatory kit to cleanse your intestines prior to the exam. While undergoing a colonoscopy may seem like a frightening prospect, it’s vitally important to your health screening process. Regular colorectal cancer screening is one of the most powerful weapons against colorectal cancer.
It can take as many as 10 to 15 years for a polyp to develop into colorectal cancer, according to the American Cancer Society. Regular screening can often prevent colorectal cancer by finding and removing polyps before they have the chance to turn into cancer. Screening can also often find colorectal cancer early, when it is most likely to be curable.
Colorectal cancer is the second leading cause of cancer death when numbers for both men and women are combined. The death rate (the number of deaths per 100,000 people per year) of colorectal cancer has been dropping for several decades. One reason for this is that colorectal polyps are now more often found by screening and removed before they can develop into cancers.
When colorectal cancer is found at an early stage before it has spread, the 5-year relative survival rate is about 90 percent. But only about 4 out of 10 colorectal cancers are found at this early stage. When cancer has spread outside the colon or rectum, survival rates are lower, the American Cancer Society states.