Colorectal cancer (informally referred to as ‘colon cancer’) is now the third most common cause of cancer-related deaths in the US. This cancer almost always starts as polyps, which are precancerous, abnormal growths in the colon or rectum.
A colonoscopy exam is the most thorough cancer screening method available, allowing your doctor to look for polyps (as well as the source for any unusual symptoms) and detect colon cancer. A colonoscopy can remove any precancerous polyps before they turn into cancer, and can also find colorectal cancer in its earlier stages when treatment has the best chance to be successful.
Almost all colorectal cancers could be prevented by regular colon screenings, and colon cancer can happen to anyone; those over the age of 45 are at higher risk, although the rate among younger adults is increasing. Colonoscopy may be recommended at any age if you have abdominal pain or symptoms of colitis, diverticulitis, or bleeding lesions.
A colonoscopy is overall very safe; in rare cases, there are a few potential complications. These may include:
- An adverse reaction to anesthesia.
- Bleeding from the biopsy site, if applicable.
- Perforation or tear in the colon or rectum wall.
You’ll be asked to take laxatives or prescription medication and will need to fast from all food for about 36 hours. If you take vitamins or other medications daily, talk with your doctor to decide if it’s okay to continue taking them before your exam. Your doctor will provide you with all the details you need well in advance of your procedure.
What Happens in Surgery?
Anesthesia will be administered so you will be asleep for the duration of the 20-30 minute screening. During the procedure, your doctor will use a long, flexible instrument, inserted through the rectum and into the large intestines, to take images of the lining of the colon and look for any abnormalities.
Most colonoscopies are quick and painless, and you won’t remember the procedure afterward.
After your colonoscopy, you’ll stay at the clinic until you wake up and feel ready to get dressed, which usually takes 10-15 minutes. Your doctor will talk to you about when you can eat (usually right away) and do your other usual activities, and about when you’ll need your next colonoscopy. This will depend on the results of your test and your risk for colorectal cancer.
After the test, you may be bloated or have gas pains. You may need to pass gas. If a biopsy was done or a polyp was removed, you may have streaks of blood in your stool (feces) for a few days. Problems such as heavy rectal bleeding may not occur until several weeks after the test. This isn’t common, but it can happen after polyps are removed.
The anesthesia medications you have received will make you sleepy, an effect that will last up to 24 hours after your procedure. For your safety, do not drive or operate machinery until the medicine wears off and you can think clearly. Your doctor may tell you not to drive or operate machinery until the day after your test. Do not sign legal documents or make major decisions until the medicine wears off and you can think clearly—the anesthesia can make it hard for you to fully understand complicated issues.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It’s also a good idea to know your test results and keep a list of the medicines you take.
- Follow your doctor’s directions for eating.
- Unless your doctor has told you not to, drink plenty of fluids. This helps to replace the fluids that were lost during the preparation for your colonoscopy.
- Do not drink alcohol for 12-24 hours.
- Your doctor will tell you if and when you can restart your medicines. You will also be given instructions about taking any new medicines.
- If you take aspirin or some other blood thinner, ask your doctor if and when to start taking it again. Make sure that you understand exactly what your doctor wants you to do.
- If polyps were removed or a biopsy was done during the test, your doctor may tell you not to take aspirin or other anti-inflammatory medicines for a few days. These include ibuprofen (Advil, Motrin) and naproxen (Aleve).