A colonoscopy lets doctors see inside your large intestine, which includes your rectum and colon. This procedure involves inserting a colonoscope (a long, lighted tube with an attached camera) into your rectum and then into your colon. The camera allows doctors to view those important parts of your digestive system.
Colonoscopies can help doctors detect potential problems, such as irritated tissue, ulcers, polyps (precancerous and noncancerous growths), or cancer in the large intestine. Sometimes the purpose of the procedure is to treat a condition. For instance, doctors may perform a colonoscopy to remove polyps or an object from the colon.
A doctor who specializes in the digestive system, called a gastroenterologist, usually does the procedure. However, other medical professionals may also be trained to perform a colonoscopy.
Your doctor may recommend a colonoscopy to help identify the cause of intestinal symptoms, such as:
- Abdominal pain
- Chronic diarrhea or changes in bowel habits
- Rectal bleeding
- Unexplained weight loss
Colonoscopies are also used as a screening tool for colorectal cancer. If you’re not at high risk of colorectal cancer, your doctor will recommend that you start having colonoscopies at age 45 and repeat the screening every 10 years after that if your results are normal. People who have risk factors for colorectal cancer may need to undergo screening at a younger age and more often. If you’re older than 75, you should talk to your doctor about the pros and cons of screening for colorectal cancer.
Colonoscopies are also used to look for or remove polyps. Although polyps are benign, they can turn into cancer over time. Polyps can be taken out via the colonoscope during the procedure. Foreign objects can be removed during a colonoscopy too.
How Is a Colonoscopy Performed?
Colonoscopies are usually performed at a hospital or an outpatient center.
Before your procedure, you’ll receive one of the following:
- Conscious Sedation This is the most common type of sedation used for colonoscopies. It puts you in a sleeplike state and is also referred to as twilight sedation.
- Deep Sedation If you have deep sedation, you will be unaware of what is going on during the procedure.
- General Anesthesia With this type of sedation, which is used rarely, you will be completely unconscious.
- Light or No Sedation Some people prefer to have the procedure with only very light sedation or none at all.
The sedative medicines are typically injected intravenously. Pain medications may sometimes also be administered.
After the sedation is administered, your doctor will instruct you to lie on your side with your knees toward your chest. Then your physician will insert the colonoscope into your rectum.
The colonoscope contains a tube that pumps air, carbon dioxide, or water into your colon. That expands the area to provide a better view.
A tiny video camera that sits on the tip of the colonoscope sends images to a monitor, so that your doctor can see various areas inside your large intestine. Sometimes doctors will perform a biopsy during the colonoscopy. That involves removing tissue samples to test in the lab. Additionally, they may take out polyps or any other abnormal growths they find.
How to Prepare for a Colonoscopy
There are several important steps to take when preparing for a colonoscopy.
Talk to Your Doctor About Medications and Health Issues
Your doctor will need to know about any health conditions you have and all the medicines you take. You may need to temporarily stop using certain meds or adjust your dosages for a period of time before your procedure. It’s especially important to let your provider know if you take:
- Blood thinners
- Nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin) or naproxen (Aleve)
- Arthritis medications
- Diabetes medications
- Iron supplements or vitamins that contain iron
Follow Your Bowel Prep Plan
Your bowel will need to be emptied of stool, so physicians can clearly see inside your colon. Your doctor will give you specific instructions on how to prep your bowel before your procedure.
You’ll have to follow a special diet. That usually includes consuming only clear liquids for 1 to 3 days before your colonoscopy. You should avoid drinking or eating anything that’s red or purple in color, as it might be mistaken for blood during the procedure. Most of the time, you can have the following clear liquids:
- Fat-free bouillon or broth
- Sports drinks that are clear or light in color
- Gelatin that’s clear or light in color
- Apple or white grape juice
Your doctor may instruct you not to eat or drink anything after midnight on the night before your colonoscopy.
Additionally, your physician will recommend a laxative, which usually comes in a liquid form. You might need to drink a large amount of the liquid solution (usually a gallon) over a specific time frame. Most people will be required to drink their liquid laxative the night before and the morning of their procedure. The laxative will likely trigger diarrhea, so you will need to stay close to a bathroom. While drinking the solution might be unpleasant, it’s important that you finish it completely and that you drink any additional liquids your doctor recommends for your prep. Let your doctor know if you can’t drink the entire amount.
Your doctor may also recommend that you use an enema before your colonoscopy to further rid your colon of stool.
Sometimes watery diarrhea can cause skin irritation around the anus. You can help ease the discomfort by:
- Applying an ointment, such as Desitin or Vaseline, to the skin around the anus
- Keeping the area clean by using disposable wet wipes instead of toilet paper after a bowel movement
- Sitting in a bath of warm water for 10 to 15 minutes after a bowel movement
It’s important to follow your doctor’s instructions carefully. If there’s stool in your colon that doesn’t allow for a clear view, you may need to repeat the colonoscopy.
Plan for Transportation
You’ll need to make arrangements for how to get home after your procedure. You won’t be able to drive yourself, so you may want to ask a relative or friend to help.
What Are the Risks of a Colonoscopy?
There’s a small risk that the colonoscope could puncture your colon during the procedure. Though it is rare, you might need surgery to repair your colon if it happens.
Although it’s uncommon, a colonoscopy can rarely result in death.
What to Expect During a Colonoscopy
A colonoscopy usually takes about 15 to 30 minutes from start to finish.
Your experience during the procedure will depend on the type of sedation you receive.
If you elect to have conscious sedation, you may be less aware of what’s going on around you, but you might still be able to talk and communicate. However, some people who have conscious sedation fall asleep during the procedure. While a colonoscopy is generally considered painless, you may feel mild cramping or the urge to have a bowel movement when the colonoscope moves or air is pumped into your colon.
If you have deep sedation, you’ll be unaware of the procedure and shouldn’t feel anything at all. Most people just describe it as a sleeplike state. They wake up and usually don’t remember the procedure.
Sedation-free colonoscopies are also an option, though they’re less common in the United States than they are in other countries, and there’s a chance that nonsedated patients might not be able to tolerate all the movements the camera needs to make to get the fullest picture of the colon. Some people who have a colonoscopy without any sedation report little or no discomfort during the procedure. Talk to your doctor if you’re interested in learning more about the pros and cons of not receiving sedation before a colonoscopy.
What Are the Complications and Side Effects of a Colonoscopy?
Complications from a colonoscopy are not common. Research suggests that only about 4 to 8 serious complications occur for every 10,000 screening procedures performed.
Bleeding and puncturing of the colon are the most common complications. Other side effects may include pain, infection, or a reaction to anesthesia.
You should seek medical attention right away if you experience the following symptoms after a colonoscopy:
- Bloody bowel movements that don’t go away
- Rectal bleeding that doesn’t stop
- Severe abdominal pain
Older people and those with underlying health issues have a higher risk of developing complications from a colonoscopy.
Care After a Colonoscopy
After your procedure is over, you’ll stay in a recovery room for about 1 to 2 hours, or until your sedation completely wears off.
Your doctor may discuss the findings of your procedure with you. If biopsies were performed, the tissue samples will be sent to a lab, so that a pathologist can analyze them. These results might take a few days (or longer) to get back.
When it’s time to leave, a family member or friend should drive you home.
You may notice some symptoms after your colonoscopy, including:
- Mild cramping
- Light rectal bleeding for a day or two (if polyps were removed)
These issues are normal and usually go away within hours or a couple of days.
You might not have a bowel movement for a few days after your procedure. That is because your colon is empty.
You should avoid driving, drinking alcohol, and operating machinery for 24 hours after your procedure. Most doctors recommend that you wait until the next day to resume normal activities. Your provider will tell you when it’s safe to begin taking blood thinners or other medications again.
Unless your doctor instructs you otherwise, you should be able to immediately return to your normal diet. You may be told to drink plenty of liquids to stay hydrated.