What to Expect Before, During, and After a Colonoscopy

If anyone in your family has had colon cancer, or if you’re nearing the age of 45, you’ve probably already been told about the importance of scheduling a colonoscopy. You may even have grown tired of your doctor telling you that it’s something you need to consider.

But the prospect of having your bowels explored on camera doesn’t exactly have most people running to book an appointment. According to the Centers for Disease Control and Prevention (CDC), less than half of adults in their early 50s have had a colonoscopy or any type of colorectal cancer screening.

This is bad news because colorectal cancer is the second most common cause of cancer death in the United States. A colonoscopy—a procedure doctors use as a tool to diagnose and screen conditions of the colon—is particularly useful for its early diagnosis. When colon cancer is found in its early stages, the five-year survival rate is 90%, according to the American Cancer Society.

Unfortunately, 4 out of 10 cases of colon cancer are found when cancer has already spread to other areas of the body. Rates of colon cancer are also rising significantly in younger people, according to 2020 statistics published in CA: A Cancer Journal for Clinicians.¹ That’s why, beginning in 2016, the American Cancer Society recommends anyone with average risk to start screening for colon cancer at age 45, or sometimes earlier depending on personal health history.

Colon cancer isn’t the only condition that a colonoscopy can catch, though. Ulcerative colitis and Crohn’s disease, both autoimmune conditions that fall under the umbrella of inflammatory bowel disease (IBD), can be detected with this test. If you’ve already been diagnosed with one of these conditions, you do have an increased risk of colon cancer, so getting regular screenings is especially important, according to a 2018 study published in the journal Clinics of Colon and Rectal Surgery.²

SELF spoke with doctors who perform colonoscopies to give us the details on what they wish people knew about this potentially life-saving screening procedure.

A colonoscopy basically is what it sounds like: a camera (scope) on a flexible rod explores your large and small intestine, looking for inflammation and pre-cancerous lesions called polyps that can grow on your intestinal walls, Matthew Bechtold, MD, a practicing gastroenterologist and professor of clinical medicine at the University of Missouri, tells SELF.

“The whole idea of screening is to prevent colon cancer from forming,” Dr. Bechtold says. “With screening, you can go in and take out these polyps or growths. Those polyps would otherwise likely grow into colon cancer over 5 to 15 years. So that’s why we want to go in there, find them, and take them out before they even have a chance of becoming colon cancer.”

If a polyp is spotted during the course of a colonoscopy, it gets removed and retrieved for further testing. If you do have one (or a few) removed, don’t worry. Polyps are common, and many found during a colonoscopy are later determined to be benign, according to a 2016 study published in the World Journal of Gastroenterology.³

Colonoscopies are also the go-to diagnostic test for conditions that affect your lower bowel, including Crohn’s disease, ulcerative colitis, and others. Your doctor might take a biopsy—remove a small piece of tissue—in your colon, which will then be looked at closely in a lab. They’ll check for signs of inflammation or changes associated with IBD.

Back to top

The answer varies, but in general if you are considered “average” risk of colon cancer—that is, you don’t have a history of bowel disease, a family history, or symptoms of concern, such as abdominal pain—it is advised that you get your first colonoscopy at or around age 45, says Keri Pinnock, MD, a gastroenterologist at Austin Regional Clinic in Texas.

Dr. Pinnock adds that if you have a history of colon cancer in your immediate family—that means a parent or sibling—you may be recommended to start getting screened earlier. “If your family member was diagnosed before 60, the guidelines are that you are recommended to have a colonoscopy at age 40 or 10 years prior to the age that that family member was diagnosed with colon cancer, whichever is sooner,” she says.

If you have inflammatory bowel disease or a genetic syndrome that makes you more likely to develop polyps or colon cancer, you may also need to increase their screening schedule, per the CDC’s guidelines. According to a 2018 study published in the Journal of Clinical Gastroenterology and Hepatology, if you’re diagnosed with IBD, you should have your first colonoscopy 8 to 10 years after diagnosis, and then every one to three years for colon cancer surveillance.⁴ Colonoscopies can be done prior to that to check on disease activity and how well you are responding to treatment. Talk with your doctor about your specific situation, and how often screening is recommended for you.

Back to top

If you’re having trouble getting over the idea of someone literally looking inside your colon, know that it’s really not that bad, or even the worst part, according to most people who’ve been through a colonoscopy. That honor goes to the bowel prep. That’s because, in order for your colonoscopy to be what doctors call a “good study,” you’ll need to follow the pre-procedure instructions from your provider carefully. These instructions may vary across providers, but there are some standard rules of thumb, according to the Mayo Clinic:

• The day before your colonoscopy appointment, you’ll need to be on a liquid diet (cue all the hunger). Clear juice (think apple or white grape), gelatin, clear broth, tea, black coffee, and sports drinks are allowed, and it’s important to stay hydrated.
• This next part is probably the least fun: You’ll be given a laxative of some sort (either over-the-counter or prescription) to empty out your bowel as completely as possible. It’s often a liquid that you have to drink quickly, and it’s not going to win any taste awards. But, it does help prep your bowel so that your provider can get a clear view of your intestine’s lining.
• On the day of your colonoscopy, you won’t be allowed to eat anything until your procedure is complete. For this reason, you may want to schedule your colonoscopy for early in the morning, if possible. Another reason to get your screening over with early in the day? A 2016 study published in the journal Surgical Endoscopy found that morning colonoscopies were better at catching benign polyps, that if not removed could become cancerous later on. Researchers posit this could be due to doctor fatigue later in the day.⁵

Back to top

When you arrive at your colonoscopy appointment, you’ll probably need to fill out some paperwork. Your nurses and doctor will introduce themselves and give you a step-by-step of what’s about to happen.

You’ll be asked to wear a hospital gown, and you’ll get prepped with an IV port for moderate or deep sedation. After the IV drop starts and the medicine kicks in, you’ll fall asleep.

Several people may be in the room during the procedure, including your gastroenterologist, a nurse or two, a technician assisting with the colonoscopy, and an anesthesiologist. The team will position you, typically lying on your left side with your legs up, while the colonoscope is inserted. The scope sends air into your intestine to slightly inflate it to obtain the best view, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Dr. Pinnock emphasizes that during the colonoscopy, a minimal area of your body is exposed, and everyone in the room is respectful of the person having the procedure. While it’s an out of the ordinary experience for you, for the team taking care of you it’s just another day at work. “You may feel uncomfortable when you get there, but when you’re in the procedure, you realize it’s almost run-of-the-mill. Everyone knows what they’re doing, so you kind of lose that discomfort. Plus, you’re sedated so quickly that you’re sleeping most of the time you’re there, anyway,” she says.

Back to top

When it comes to looking for signs of colon cancer, colonoscopies are mainly looking for polyps, also known as adenomas. If any polyps are found during your colonoscopy, it means the screening had a “positive” or abnormal result. However, if any tissue was removed during the procedure, it will still take a few days to get biopsy results that will tell you if any cancerous or precancerous cells were detected.

When it comes to diagnosing ulcerative colitis and Crohn’s, Dr. Bechtold says a colonoscopy may be ordered if you’re experiencing certain symptoms like rectal bleeding, abdominal pain, and recurring constipation. Colonoscopies can look at the lining of your colon and detect inflammation or ulcers that are caused by ulcerative colitis and Crohn’s disease. A colonoscopy may be done prior to starting a new treatment regimen for IBD and repeated later on to see if the treatment is working well.

Back to top

While all your colonoscopy prep probably felt like an eternity (mostly in the bathroom), the procedure itself really only takes about 30 to 60 minutes, per the NIDDK. If polyps are removed during the procedure, it may take slightly longer. If you’ve had anesthesia, and most people do, you’ll also need to hang out in recovery for a while. Factoring that in—from when you check in to when you are ready to leave—the entire procedure typically takes about an hour and a half.

Back to top

After the colonoscopy is complete, you will be taken to a recovery area while the anesthesia wears off. You may feel a little bit groggy, or you might not. You also may feel like you have to let out an epic toot. That’s normal, and one of the few times in life you’re actually encouraged to do so. Once you’re fully mobile, you’ll be discharged to a person you trust to drive you home. (You’ll probably be feeling fine, but operating a vehicle right after any type of sedation is not recommended for 24 hours, according to the NIDDK).

You can eat whatever you’d like as soon as you wake up, though Dr. Bechtold cautions to take it easy to avoid digestive discomfort. “I wouldn’t go to a buffet and overdo it, but you can eat regular food that you want to eat. I think that most folks that I scope go out to eat after they’re done, you know, because they’re hungry and that sounds nice,” he says.

Back to top

As with any procedure, there are some risks for getting a colonoscopy, but major complications are extremely rare. Any possible side effects are minimal when compared to the risk of having undiagnosed colon cancer or inflammatory bowel disease.

Potential colonoscopy risks include:

• Rectal bleeding, especially if tissue is removed during the procedure
• Allergic reaction to anesthesia medication
• Bowel perforation (a hole in the bowel wall)

To give you an idea of how low the risk that we’re talking about is, bowel perforation from a colonoscopy was around 4 in every 10,000 procedures, according to data collected in 2016 and published in JAMA.⁶ As Dr. Bechtold notes, if you go to an experienced provider for your colonoscopy, the risks of these already rare complications decrease even more.

Back to top

Again, for people who are not at higher risk for colon cancer, colonoscopies don’t need to be done annually or even biannually. If no polyps are found, and you are in the average risk category, you won’t have to get another colonoscopy for ten years.

If your doctor finds more than one polyp, a large polyp (more than one centimeter in diameter), or cancerous lesions during the screening, you’ll likely need to get it done again sooner. A family history of bowel cancers may also mean you have to get another screening sooner rather than later. If you are diagnosed with IBD, you’ll likely need screenings every few years.

Back to top

A colonoscopy isn’t the only type of test available for various gastrointestinal conditions. Another option is a “virtual colonoscopy,” which is a less invasive type of screening. It’s been gaining popularity because it can be done without the insertion of the colonoscope. This screening is a CT scan that images your entire pelvic and abdominal area. The downside of this type of screening is that polyps can’t be removed during it. If abnormal tissue is found, you might have to have a colonoscopy to remove it anyway. (Oh, and that also means two bowel preps, since a CT also requires one). 

There are also stool screening tests available that can detect the presence of cancerous or precancerous cells in your colon, as well as markers of inflammation that could indicate IBD. These tests are relatively new, and they have a high incidence of false positives, according to a 2017 study published in the journal Cancer Epidemiology, Biomarkers and Prevention.⁷ When you get any type of positive result from a stool screening test, you’ll need to come in and have a regular colonoscopy.

These other screening methods don’t have the same level of accuracy as a traditional colonoscopy, but they are considered reasonable alternatives—and they’re certainly better than not getting screened at all.

“The best screening test is the one that the patient will do,” Dr. Pinnock says. “As long as they have all the information, I’m fine with other types of tests. Because it means they’re getting a screening test, and that’s the most important thing.”

Back to top

Sources:

1. CA: A Cancer Journal for Clinicians, Colorectal Cancer Statistics, 2020
2. Clinics of Colon and Rectal Surgery, Colorectal Cancer in Inflammatory Bowel Disease
3. World Journal of Gastroenterology, Surveillance of Colonic Polyps: Are We Getting It Right?
4. Clinical Gastroenterology and Hepatology, When Do You Start and When Do You Stop Screening for Colon Cancer in Inflammatory Bowel Disease?
5. Surgical Endoscopy, Morning Colonoscopies Are Associated With Improved Adenoma Detection Rates
6. JAMA, Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
7. Cancer Epidemiology, Biomarkers and Prevention, Long-Term Follow-Up of Patients Having False-Positive Multitarget Stool DNA Tests After Negative Screening Colonoscopy

Related:

• Everything You Need to Know About Ulcerative Colitis Flare-Ups, From Causes to Treatments
• Ulcerative Colitis Causes and Risk Factors, Explained
• Ulcerative Colitis vs. Crohn’s Disease: What’s the Difference?