Colonoscopy is a test used to check for and remove polyps from the colon. It is also a way to look for signs of other diseases such as colon cancer.
Before the procedure begins, you will need to follow bowel prep instructions exactly as directed. It is important to arrange for a friend or family member to drive you home because of the sedative used for the test.
A colonoscopy lets your doctor look at the inside lining of the large bowel (colon) and rectum. It is one of the most comprehensive methods for evaluating abnormalities in the bowel and checking for signs of cancer. A doctor may also use it to remove polyps, which are abnormal growths. A colonoscopy is usually done under sedation and can take 30 to 60 minutes.
Your bowel needs to be empty for the test, so you must not eat solid food for 24 hours before the procedure and drink only clear fluids like water, Gatorade, or tea without milk or coffee. You will need to stay close to a toilet on the day of the test. You should have the test in a hospital or outpatient clinic.
You lie down on the exam table and your doctor inserts a long flexible tube called a colonoscope into your back passage (rectum) and up into your large bowel. The end of the colonoscope has a light and camera that sends an image to a monitor. The endoscopist may pump air into your large bowel to see the lining better. You may feel a brief period of discomfort as the tube is moved or air is introduced into your bowel.
During the examination, your doctor can also remove small pieces of tissue (biops) for further testing. Most colon polyps are harmless, but they can be a sign of cancer or other problems. Your doctor will send any biops or other tissue samples to a laboratory for analysis. The results can be seen on your patient portal and you will receive a call from your doctor to discuss the findings.
After the procedure, you will need to wait until the sedation or anaesthesia wears off before you can go home. It is best to have someone to drive you home as you will be too drowsy to do so safely. You should also not operate any machinery or sign legally binding documents until the anaesthetic has worn off.
A colonoscopy is a safe and effective procedure. But it is important to understand the risks and benefits of the test before you decide whether to have it.
Preparation
You will be given specific instructions in a letter or on the phone about changing your diet and cleaning out your colon for the test. The preparation will involve taking a combination of laxatives that will cause diarrhea and frequent trips to the bathroom. You will also be told not to eat anything solid for a day or so before the procedure. It is important to follow the instructions exactly because the procedure can only be done properly if your colon has been fully cleaned out.
In the days leading up to the test, it is important to follow a low-fiber (low residue) diet that excludes whole grains, nuts and dried fruits. A clear liquid diet is usually permitted, including juices, tea, water and some milk products. Your doctor will tell you the exact list of foods to avoid. You should also be sure to drink lots of fluids, especially a mixture of clear broth or bouillon and black coffee or tea. It is important to drink this fluid even if you don’t feel thirsty.
A few days before the colonoscopy, you will need to start drinking a special solution to empty your bowels. You will drink a few sachets of this preparation each day, starting the evening before and continuing on through the morning of the procedure. This fluid should be drunk through a straw to reduce the unpleasant taste and to help you swallow it quickly. You will need to be close to a toilet as you will need to use it frequently.
The night before and morning of the procedure, you should also take a series of laxatives. These may be in pill form, a powder that you dissolve in liquid or an enema. You will need to follow your doctor’s exact instructions as these will differ between patients.
You will be given pain medicine and a sedative for the procedure, so you will need to have someone drive you home afterward. The procedure itself usually doesn’t cause any discomfort, but you might feel some pressure or cramping. The sedative helps to reduce this.
Procedure
Your doctor will give you instructions on how to prepare for the colonoscopy. The prep will require you to drink a combination of liquids and pills or have an enema to empty your bowel. The preparation is important because if the colon is full of stool your doctor will not be able to see any polyps or other abnormalities. You should start the prep a day or two before your exam.
During the procedure you will lie on a table and are given medication usually though an IV to help you relax and keep you comfortable. This is called sedation or anesthesia. You will be monitored for heart rate, breathing and blood pressure. You may feel some cramping or gas pains during the procedure which should resolve quickly once the anesthesia wears off. Most people do not remember the procedure once they are awake.
You will have a flexible tube with a camera at the end (called a colonoscope) that is guided into your anus and up into your rectum and colon. The doctor will then be able to view the area and if needed can remove any tissue samples that are abnormal. It typically takes less than an hour to perform the test.
People of average risk for colorectal cancer are recommended to get screened every 10 years starting at age 45. Your doctor will assess your risk and may recommend screening earlier or more often depending on your family history and other health factors.
If you have a history of polyps or other colon disease your doctor will likely recommend a colonoscopy to look for new ones. You will be advised about the procedure and what to expect so that you can make an informed decision about whether or when you should have this test done. If your doctor finds any polyps or other abnormalities they will most likely want to do a biopsy of the tissue. This can be done at the same time as your colonoscopy. If the results show that you have colon cancer your doctor will discuss treatment options with you.
Recovery
A colonoscopy is usually done in an outpatient setting, but sometimes it is performed at a hospital. Before the procedure begins, a health care professional will insert an intravenous needle into your arm or hand to give you sedatives, anesthesia, or pain medication so you won’t feel anything during the procedure. It is best to arrange for someone to drive you home from the hospital afterwards, since the sedatives may affect your ability to operate a vehicle safely.
You will be asked to change into a hospital gown and you will speak with a nurse or doctor who will explain possible complications. A nurse will also check your vital signs to ensure you are stable before the procedure. You may have some cramping and bloating after the procedure, as a result of the air that enters your colon during the test, though this should go away within an hour. You can take over-the-counter pain relievers if needed.
During the procedure, the doctor will view the inside of your colon, and may remove polyps if necessary. Typically, the test takes about 30 to 60 minutes. After the procedure is finished, you will be moved to a recovery room and monitored by a nurse until your vital signs return to normal.
Once you are awake and the sedative has worn off, your doctor will give you discharge instructions and tell you the results of the colonoscopy. Although it is rare to have complications after a colonoscopy, you should call your doctor right away if you experience vomiting, fever, irregular heartbeat, severe abdominal or rectal pain, bloody stool, or abnormally heavy or frequent bowel movements.
To prevent colonoscopy-related complications, you should avoid drinking alcohol and taking strenuous exercise before and after the procedure. Instead, you should drink plenty of fluids to stay hydrated. Water, black tea, or coffee are good choices. You should also eat foods that are easy on the digestive tract, such as scrambled eggs, mashed potatoes, skinless chicken, fish, or soups and broths. Avoid high-fiber foods as these can irritate your digestive system and cause discomfort.
