Colonoscopy
“A colonoscopy is the most effective screening option for early detection. It’s the only screening exam that not only checks for colorectal cancer, but can also prevent it.”
Elizabeth Lindsey, M.D., Gastroenterology, Williamson Medical Group, Franklin, TN.
Image credit: Gastroenterology Consultants of San Antonio
If you know someone with a condition like Inflammatory Bowl Disease (IBD) or is soon turning 45, the doctor has most likely mentioned the term “colonoscopy” before. You may be wondering, what is a colonoscopy and how is it useful?
What is a colonoscopy and why is it important?
Colonoscopies are medical procedures that are used to find changes or abnormalities in the rectum or large intestine (colon). Gastroenterologists use colonoscopies to find any damage to your intestines, diagnose or prevent cancer, find and remove precancerous tumors/polyps, or take a biopsy (a tissue sample taken during the colonoscopy). While colonoscopies are invasive procedures, they are painless and relatively quick. They are harmless exams that offer lots of insight on the state of your body – especially your guts. According to iData Research, in 2017, more than 19 million colonoscopies were performed in the United States alone.
There are three parts to any medical procedure: The preparation, the procedure, and recovery, but for exams like colonoscopies, there is a fourth: results. Let’s go through them.
How to prepare for a colonoscopy exam?
The main goal for preparation for a colonoscopy is to clean out the colon (also known as the large intestine) and small intestine. Hence, you will have a diet light in raw fruits, nuts, seeds, vegetables, or anything that will add residue to your stool. Keep your diet low in foods with fiber. Your doctor will most likely ask you to not eat any solid food 24 hours before the exam.
To clean out your colon thoroughly, you will need to take a liquid laxative solution. There are several available on the market. Some examples of laxative brands include MiraLAX and Dulcolax. The majority of these simply provoke more frequent bowel movement. You will head to the bathroom more often, and as a result, your colon will be cleaned out. Ask your doctor about which solution you should have. For most cases, the solution is taken the day before the exam, split between the night before and the day of the procedure. You have half the solution in the night and the other half, 4-6 hours before the procedure. Dividing the solution into two main doses is usually better tolerated and is more effective at cleansing your colon.
If you finish your solution, but find your stool is not clear, tell your doctor. The colonoscopy may have to be postponed to a later time for more cleansing to happen. If you can’t finish the solution, try (a) drinking it through a straw, (b) stop, walk around and come back, (c) ask your doctor if anything can be added for better taste, or (d) if you feel sick or are vomiting, call your doctor.
What happens during a colonoscopy exam?
Before the colonoscopy begins, the doctor will start an IV and administer a sedative to ease any pain or discomfort. General anesthesia is administered through the IV. Doctors start an IV by poking your arm with a needle and leaving a plastic catheter (a thin pipe) in its place.
During the colonoscopy, the doctor inserts a flexible tube-like instrument called a Colonoscope through your anus, through the rectum, and into the colon. The Colonoscope has a camera and light embedded at the tip, providing well-lit, accurate photos as the device moves through the colon. The camera provides a live feed to a nearby computer monitor for the doctor to see. Sometimes, a doctor may take a biopsy, which is a small sample of your intestine tissue. Most often, they send the sample to a lab for analysis. A colonoscopy usually takes 30 minutes to an hour to complete. Once the colonoscopy is over, the Colonoscope is removed out back through the anus, and you are taken to a rehab room.
Diagram of a Colonoscopy. Image Credit: John Hopkins Medicine
A Colonoscope with parts. Image Credit: NCBI
Who performs the colonoscopy exam?
A colonoscopy requires many different people doing many different tasks. The person who performs the colonoscopy is a Gastroenterologist. Gastroenterologists perform the most colonoscopies out of any other specialty, and are therefore 5 times more likely to find colorectal cancer in the gut than a non-Gastroenterologist! When a Gastroenterologist is properly trained to do a colonoscopy, they can perform it well, apply the proper treatments, and correctly interpret the results. The American Society for Gastrointestinal Endoscopy (ASGE) advises that people performing colonoscopies should receive training about colonoscopy in a surgical residency, or complete a fellowship program in gastroenterology. The Gastroenterologist should also be trained in the removal of polyps, should the need arise. When seeing who is performing your colonoscopy, you should see their rate of perforations per procedure. A perforation is when the doctor makes a hole in the colon, which is not good. The rate should be below 1 in 500 exams, but most experts have their rates well below 1 in 1000 exams!
How to recover after a successful colonoscopy?
Once your colonoscopy ends, you will stay in rehab until the sedative wears off. You will feel groggy and tired, so you can’t drive yourself home. Sedative effects can last up to a day, so do not operate any machinery until the day after the colonoscopy. Your doctor may not send you home unless you have someone ready to take you home. Immediately after the colonoscopy, you may also feel gassy or bloated. This is because the air was trapped in your intestines for quite a while. Within 30 minutes to an hour, the feeling should subside. If you had a biopsy, then your doctor may suggest a temporary special diet that allows your intestines to recover from the lost tissue. You may not have another bowel movement for another day or two after the procedure. Once you do, you may notice a little bit of blood. This is common. However, if the bleeding lasts more than a day, becomes a lot more, or is clotting, contact your doctor. You should also contact your doctor if you have a fever of 100 degrees Fahrenheit or higher, severe pain in your stomach, or dizziness. Most people come out from colonoscopies fine and healthy, so there shouldn’t be anything to worry about.
How to deal with the results of a colonoscopy?
A few days after your colonoscopy, your doctor may contact you and send you images of your intestine and their thoughts on them. You will see plenty of photos of your intestines. If there is any red spot, that is most likely a spot where your intestine is injured and bleeding. The numbers are marked accordingly (ex: number one is the first picture, when they were just about entering the colon, and so on and so forth). I suggest having a diagram of the intestines in front of you, so you can see where there is damage to your intestines. Correspond a bend in the intestine in the photo to a bend in the diagram. Going over the photos after a colonoscopy is very interesting as there are very few medical procedures which provide you this level of visibility inside your own body!
What are the risks of a colonoscopy?
Most colonoscopies are safe and pose no harm. But sometimes it can cause problems and injuries. Some examples include: tears in the colon lining, heavy bleeding, infection or inflammation of pouches in the colon called diverticulitis, problems with people who have blood vessels or heart problems, and severe abdominal pain. These rare problems can lead to surgery, hospitalization, blood transfusions, or (this happens very rarely) death. Colonoscopies are also not the most convenient medical exam. You have to prep 24 hours in advance by taking laxatives and restricting your diet. Also, since anesthesia is administered during the exam, you will have to get someone to take you home afterwards. You may miss a day of work or school.
Colonoscopies are relatively easy procedures, and offer a lot of information on the state of your intestines. The American Cancer Society advises colonoscopy for people 45 and older to screen for colorectal cancer, and the Crohn’s and Colitis Foundation of America recommends that 8 years after your diagnosis of IBD, you start getting a colonoscopy every couple of years to look for signs of colorectal cancer and pre-cancerous tissue.
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An Astounding 19 Million Colonoscopies are Performed Annually in The United States. iData Research, https://idataresearch.com/an-astounding-19-million-colonoscopies-are-performed-annually-in-the-united-states/. Accessed 9 Oct. 2021.
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