A colonoscopy is a routine and commonly performed procedure, in which a highly trained doctor (called a gastroenterologist) will insert a colonoscope (a flexible tube containing a camera at the tip) into the rectum and colon (large intestine), to carefully inspect the colon. The scope is about the width of your finger, and the procedure is typically painless, as patients are sedated. A typical colonoscopy takes about 20 to 30 minutes.

The most common reason to have a colonoscopy is as a screening test for colon and rectal cancer. Colorectal cancer is the third leading cause of cancer deaths in the United States and the average risk for developing colorectal cancer is about 6 percent. Colonoscopy is a safe, proven and effective means to detect colon cancer. Colonoscopy can also be useful for the evaluation of conditions, such as bleeding, chronic diarrhea and anemia (low blood counts).

Polyps are abnormal growths of tissue that form on the lining of the colon. While many benign polyps are harmless, others are considered precancerous. Precancerous polyps carry the potential to turn into cancer. They are generally slow growing, so a small precancerous polyp may take 10 to 15 years to turn into cancer. Approximately 30 percent of people age 50 and older have precancerous polyps. Colonoscopy permits the early detection and removal of polyps. Because almost all colorectal cancers start as small polyps, the removal of these polyps at the time of colonoscopy is an effective means to prevent colorectal cancer. The removal of polyps (polypectomy) is a painless procedure.

A colonoscopy is generally a well-tolerated procedure. Most patients are given a sedative and pain medication through an IV that is placed by the nurse before the procedure. Because of these medications, most patients do not experience pain or remember the procedure. You will typically lie on your left side during the procedure, although in some cases, you may be repositioned. After your colonoscopy, you will spend about 30 minutes in the recovery area. During a colonoscopy, your doctor carefully inspects the colon and may remove polyps (polypectomy) or take biopsies (painless removal of a small sample of the tissue lining).

A colonoscopy is a safe and routine procedure, but like any procedure, it does carry some risks, which are small and uncommon. Statistics show that our rate of major complications (one  in 2,000) is significantly lower than the national average. The most serious complication is a perforation, or a tear of the wall of the colon. In some cases, this might require emergency surgery. Bleeding is another possible complication, which can occur at the site where a polyp is removed or biopsied. Bleeding typically stops on its own, but may require additional treatment.

Patients receive a sedative (medication related to Valium) and a pain killer (medication related to morphine) during the procedure. This type of sedation is called moderate sedation, sometimes described as "twilight sleep." Most patients are very comfortable, experience no pain and have no memory of the procedure. Technically, patients are conscious during these procedures, are able to respond to questions, and can maintain their blood pressure and breathing at safe levels on their own. Some patients may wake up toward the end of the procedure. They may even watch the procedure on a monitor (most patients find this very interesting) and remain completely comfortable. If needed, sedatives can be increased. This type of sedation is different from general anesthesia, which is a deeper level of sedation in which patients are unconscious. In these cases, an anesthesiologist is needed to help the patient to regulate their blood pressure and breathing. Any form of sedation does carry risks, but these risks are very low with moderate sedation.

You will be monitored closely in the recovery area as the sedatives wear off. You may experience some cramping and bloating and you will be encouraged to pass flatus, which will help you to feel better. Because sedatives may impair your judgment and coordination, you will be required to have someone drive you home and to stay with you for a short time after the procedure. There are generally no restrictions on what you can eat after a colonoscopy. Your doctor will give you specific instructions on whether you should take or avoid certain medications, depending on the findings of your colonoscopy. If your doctor took biopsies or removed polyps, you will be contacted separately with those results.

On rare occasions, the scope cannot be advanced all the way around the colon. In cases like this, your doctor will discuss with you different alternatives. Colonoscopy has been considered the “gold standard” for examination of the colon and rectum, however, polyps and other findings can sometimes go unseen at the time of colonoscopy. You can minimize this risk by taking your bowel preparation as instructed in order to clean the colon as effectively as possible.

Yes, you need to finish all of the prep. National studies have demonstrated that the most effective way to cleanse the colon is to take the entire bowel preparation solution split into two separate doses. This ensures the colon is clean and minimizes the need to reschedule your procedure.

It’s best to be at home when you begin the prep as bowel movements start very quickly.

Please take all of your medications as prescribed by your other doctors, unless specifically instructed by your gastroenterologist to do otherwise.

The general rule is if you can see through it, you can have it. You should stay well hydrated while drinking the prep, so feel free to have as much of the clear liquid diet the night before as is tolerable to you.

A&D ointment, Desitin and petroleum jelly can be applied to the affected area. Non-alcohol containing wipes (baby wipes) can be used for cleansing.

Medications commonly given during colonoscopy can temporarily impair judgment and coordination.

You should be back to normal by the day following your procedure.