What Is a Colonoscopy?
Key takeaways:
During a colonoscopy, a gastrointestinal specialist inserts a flexible camera into the anus to look at the large intestine. For comfort, this is done while you are sedated.
People often get a colonoscopy to screen for cancer. But it can also look for causes of symptoms such as weight loss, diarrhea, blood in stool, or abdominal pain.
Colonoscopies are common and safe procedures that most people tolerate well. For most, the bowel prep before the procedure is the worst part.
A colonoscopy is a procedure in which a specialist, called a gastroenterologist, inserts a flexible camera into the anus. This is so they can look at the inside of the large intestine (colon) for any signs of disease. Almost everyone’s healthcare provider will recommend this test to screen for colon cancer at some point in their life. But it can also look for other conditions such as inflammatory bowel disease, diverticulosis, or sources of bleeding. This makes it a pretty common medical procedure. We’ll go into detail about what to expect if you are considering or planning to have a colonoscopy.
What does a colonoscopy test?
There are a lot of reasons you may get a colonoscopy.
One of the most common reasons is to screen for colon cancer, the third most common type of cancer (excluding skin cancer). This procedure can look for tumors or abnormal growths in the colon (called “polyps”) that can eventually turn into cancer. A colonoscopy is an option for colon cancer screening starting at age 45. But some people get one earlier than that if they are at high risk for colon cancer. Most people get one every 10 years for screening.
You might also need a colonoscopy to check for causes of certain symptoms or conditions that affect the colon. A colonoscopy allows your provider to look at the appearance of the intestinal lining and to take a biopsy of areas that appear abnormal. This can help diagnose a number of different medical conditions. Some examples of symptoms that might lead to a colonoscopy are:
Abdominal pain: This might come from conditions like inflammatory bowel disease (IBD) or food intolerances.
Unexplained weight loss: This could be a sign of colon cancer or intestinal malabsorption.
Bleeding from the anus or blood in the stool: This can come from hemorrhoids, diverticula (pouches in the colon), colon cancer, or IBD.
Change in bowel habits: Changes may come from any of these conditions.
Why it matters: Routine colorectal cancer screenings can help catch the disease early. One man shares what he learned about the importance of colonoscopies after his sister died from rectal cancer at age 56.
What to expect: Colonoscopies may seem uncomfortable — but they help safeguard your future health. Three people share their experiences with the procedure.
How much they cost: Most insurance plans cover colonoscopies, though you might have some out-of-pocket costs. Here’s what you can expect to pay, and what factors might affect the price.
What to expect during a colonoscopy
A colonoscopy may sound like an uncomfortable procedure. But you actually won't feel much during a colonoscopy because you’ll be sedated. These aren’t medications that will knock you out completely (like general anesthesia for a big surgery). You’ll be pleasantly sedated, and you won't feel pain or be aware of what is happening.
Once sedated, a specialist inserts a long, thin, and flexible camera into the anus. They then gently inflate the colon with air, like a balloon. This camera then travels through the colon while your provider looks at the inside of the colon for any abnormal areas. Depending on what they find, they may take small tissue biopsies or remove polyps for testing.
After the procedure, you’ll go to a recovery room to allow the sedation medications to wear off. As you start to wake up, you’ll likely feel bloated and start to pass some gas. This is normal — it’s just the air that was infused into the colon during the procedure. A lot of people wonder if they will poop during or immediately after the procedure. Usually that doesn’t happen — especially if you did the colon prep (more on that below). You’ll start having normal bowel movements in 2 to 3 days.
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Tips to prepare for your colonoscopy
You will get specific instructions from your provider about what to do before your colonoscopy. But here is what you can generally expect in the days leading up to a colonoscopy.
You’ll likely have to make some temporary changes in your diet. First, you’ll eat a clear liquid diet for 1 or 2 days before the procedure, which might consist of:
Fat-free broths
Gelatin
Black coffee or tea without milk or cream
Strained juices (but not orange juice, because it may have pulp or sediment in it)
And it’s important to remember that you should avoid any foods that are red or purple in color because they can be mistaken for blood during the procedure.
The night before your procedure, your healthcare team will ask you to avoid eating or drinking anything after midnight. And the way you take your medications might temporarily change as well. You’ll likely take most of your normal medications with small sips of water. But some medications might not be safe to take before your procedure. You’ll want to check with your provider about these medications, in particular:
Aspirin
Blood thinners (anticoagulants)
Diabetes medications
NSAIDs (nonsteroidal anti-inflammatory drugs), such as ibuprofen
Iron supplements
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In addition to changes in your diet and medications, an important part of colonoscopy preparation is using a laxative to empty out the intestine.
What is a bowel prep?
You’ll get instructions to do a colon cleansing routine, called a “bowel preparation” (bowel prep) 1 or 2 nights before the procedure. Honestly, this isn’t anyone's favorite part of the procedure. The prep is a large volume of liquid with laxatives in it that makes you poop — a lot. Although they all work in a similar way, there are many different options for bowel prep routines:
While it might not be fun, a bowel prep is very important. If there’s still stool in the colon during the procedure, your provider might miss small polyps or other concerning areas. This means serious conditions like colon cancer might go undiagnosed. And if there’s still a significant amount of stool in the colon, your provider may not be able to advance the camera at all. So a bowel prep is necessary for the procedure to be as accurate and complete as possible.
Will I be in pain after my colonoscopy?
You shouldn’t have a lot of pain after a colonoscopy. It is normal to experience some mild cramping and bloating. But if you’re having severe pain, talk with your provider. This could be a sign of a serious complication of the procedure called a “bowel perforation,” which is when a hole forms in the wall of the colon.
There also may be some blood in the stool after this procedure, especially if your provider took biopsies or removed polyps. The blood should stop after a few bowel movements. But serious bleeding may occur. Talk with your provider if you are having any blood in your stool after the procedure.
Yet, perforations and serious bleeding are rare. Most people have no trouble after this procedure.
The bottom line
No one likes to hear they need a colonoscopy. But it is a common diagnostic test. You’ll probably find that a lot of people you know have had one, especially if you’re over 45. The bowel prep is most likely to be the most uncomfortable part. But at least this part can happen in the comfort of your own home. The procedure itself is typically well tolerated and comfortable. It’s safe, too. So don’t let the idea or fear of this procedure stop you from scheduling one. It’s an important way to keep up with your health.
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References
American College of Surgeons. (2021). Colonoscopy.
Cancer.net. (2021). Colorectal cancer: Screening.
Cancer.net. (2021). Colorectal cancer: Statistics.
National Institute of Diabetes and Digestive and Kidney Diseases. (2017). Colonoscopy.
U.S. Preventive Services Task Force. (2021). Colorectal cancer: Screening.
