What Is a Colonoscopy? A Comprehensive Look

A colonoscopy is a medical procedure that plays a crucial role in colorectal health by providing a way to comprehensively visualize the colon and rectum. This article takes an in-depth look at:

• What a colonoscopy is
• The colonoscopy’s pivotal role in colorectal cancer screening and diagnosis
• Who is and is not eligible for a colonoscopy
• How to prepare for a colonoscopy
• What to expect during the procedure

To begin, a colonoscopy is a medical endoscopic examination used to visualize the inside of the large intestine (colon) and rectum. It involves the use of a flexible, thin tube called a colonoscope, which is equipped with a camera and a light source and inserted through the anus and rectum, allowing gastroenterologists to navigate the colon's entire length.

Colorectal cancer screening and diagnosis

Colorectal cancer ranks as the third most common cancer in the United States, but when caught early, it is highly treatable. Being the gold standard in early detection, colonoscopies play a pivotal role, as they enable the identification and removal of polyps (small growths) along the colon's inner lining. This proactive measure significantly reduces the risk of cancer development.

Diagnostic versatility

A colonoscopy may also be used to identify potential tumors that are subsequently removed and sent for biopsy and a more definitive diagnosis. Beyond cancer screening, colonoscopies serve as a diagnostic tool for other various gastrointestinal issues. These may include unexplained abdominal pain, alterations in bowel habits, rectal bleeding and inflammatory conditions like ulcerative colitis.

Colonoscopies are recommended for individuals depending on their age, risk factors and symptoms.

Age and risk factors:

• Adults aged 45-75 are recommended for routine colorectal cancer screening.
• Those with a family history of colorectal cancer or polyps may need to start earlier.
• Individuals with certain genetic syndromes, such as Lynch syndrome or familial adenomatous polyposis (FAP).

Individuals with symptoms:

• Anyone experiencing gastrointestinal or colorectal cancer symptoms like rectal bleeding, persistent diarrhea, or unexplained weight loss.

While colonoscopies are generally safe, there are situations where they may not be recommended. Below are some of the possible reasons you may not be eligible for a colonoscopy; you should always consult your healthcare provider prior to the procedure.

Severe heart or lung conditions: Individuals with severe heart or lung diseases, such as congestive heart failure or severe chronic obstructive pulmonary disease (COPD), may not be suitable candidates for a colonoscopy. These conditions can significantly increase the risk of complications during the procedure. Sedation and changes in oxygen levels can pose risks to individuals with compromised cardiac or respiratory systems.

Recent abdominal surgery: Abdominal surgery is a form of treatment that involves the manipulation and repairing of abdominal tissues and organs by cutting open the body. It's essential to allow sufficient time for the surgical site to heal and for any inflammation to subside before performing a colonoscopy. This reduces the risk of complications.

Acute gastrointestinal conditions: Individuals experiencing acute gastrointestinal conditions like severe bowel obstruction may need to delay a colonoscopy. These conditions can make the procedure technically challenging and potentially increase the risk of complications.

In cases of active bleeding, addressing the bleeding source may take precedence before a colonoscopy can be safely performed.

Pregnancy: Pregnant individuals are not recommended to undergo a colonoscopy unless it's deemed medically necessary. The procedure, though largely safe, can pose potential risks to the developing fetus. If a colonoscopy is essential during pregnancy, it should be carefully evaluated and the risks and benefits should be discussed with the patient and their obstetrician. If needed, the procedure is normally recommended for the second trimester of the pregnancy rather than the first or third.

Proper preparation is essential to ensure the procedure is successful.

Pre-procedure consultation

Before the colonoscopy, you'll have a consultation with your gastroenterologist or healthcare provider. This is an opportunity to discuss any concerns, medications or medical conditions you have that may impact the procedure.

They will also provide you with detailed instructions on how to prepare for the colonoscopy, including dietary restrictions and bowel cleansing prior to the procedure.

Dietary restrictions

Typically, a few days before the colonoscopy, you will need to follow a clear liquid diet. This diet includes:

• Clear broths (chicken or beef)
• Clear fruit juices (without pulp)
• Clear popsicles
• Gelatin (without fruit)
• Clear sports drinks (avoid red or purple colors)
• Coffee or tea (without milk or cream)

Medication adjustments

Ensure to inform your healthcare provider about all medications you are taking. Some medications may need to be adjusted or temporarily stopped before the procedure to minimize risk and complications. For instance, blood-thinning medication can cause bleeding to happen more easily, and may need to be paused under medical guidance ahead of a colonoscopy.

Colon preparation and bowel cleansing

The day before the colonoscopy, you will be required to cleanse your colon thoroughly. This is critical for an unobstructed view and a successful examination. The preparation often involves taking a prescribed laxative or bowel-cleansing solution.

Common bowel preparations include polyethylene glycol (PEG) solutions, magnesium citrate or sodium picosulfate-based products. You will be given specific instructions on how to take the bowel preparation medication, including the timing and quantity. Expect multiple bowel movements as the colon is thoroughly cleaned out. Do not be alarmed, and remember to stay hydrated during this process by drinking clear liquids.

Dietary restrictions and fasting the day before the colonoscopy

On the day before the colonoscopy, you will continue to follow the clear liquid diet. Solid foods, dairy products and liquids with red or purple colors should be avoided. It's crucial to adhere strictly to the dietary restrictions to ensure a clear colon.

Typically, you will need to fast for a specific period before the colonoscopy. This ensures that the colon remains empty for the procedure.

Your healthcare provider will specify the duration of fasting, which usually includes refraining from consuming any food or liquids, including water, for a specified time before the procedure.

Transport arrangements after the colonoscopy

Since sedation is typically used during a colonoscopy, your senses and judgment may be temporarily immediately after the procedure. Arrange for someone to accompany you to the medical facility and drive you home afterward to ensure safe travels.

On the day of the procedure, you'll check in at the medical facility. The staff will review your medical history, medications and ensure you understand the procedure and its risks. You'll be asked to sign a consent form confirming your understanding and agreement to proceed with the colonoscopy.

Patients who are unable to complete the bowel preparation process adequately may not be eligible, as a clear and clean colon is essential for a successful colonoscopy. If a patient is unable to follow the prescribed dietary restrictions or complete the bowel cleansing regimen, the procedure may need to be rescheduled to ensure a thorough examination.

Pre-procedure preparation

After check-in, you'll change into a hospital gown and may be provided with a robe for modesty. An IV line may be inserted to administer sedatives and fluids during the procedure.

Once ready, you'll be positioned on your left side on a specially designed procedure table. Your knees will be drawn up towards your chest to create a comfortable angle for the colonoscope insertion.

The colonoscopy procedure

Once you're comfortably positioned, the gastroenterologist or trained endoscopist will begin the procedure. Throughout the procedure, you will be sedated to minimize discomfort. Your vital signs, such as heart rate and oxygen levels, are closely monitored by trained medical staff.

The colonoscope, a thin, flexible tube about the thickness of a finger, is lubricated and gently inserted through the rectum and into the colon. The colonoscope contains a powerful light source at its tip and a high-definition camera, which provides real-time images of the colon's inner lining.

As the colonoscope is advanced, the camera sends images to a monitor in the procedure room. The medical staff carefully navigates the colonoscope through the colon, examining the entire length. If any abnormalities, such as polyps or lesions, are detected, they may be biopsied or removed by passing small tools through the colonoscope. These samples are sent to a laboratory for further examination to determine if they are cancerous or precancerous.

To provide a clear view, a small amount of air may be gently introduced into the colon through the colonoscope. This expands the colon's walls, allowing for better visualization. You may experience some discomfort and a feeling of bloating.

Once the entire colon has been examined, the colonoscope is carefully withdrawn. The images captured during the procedure are reviewed by the medical team and you will be allowed to return home.

If you have any questions or concerns about the preparation process, do not hesitate to reach out to your healthcare provider for clarification and guidance. Your cooperation and attention to detail play a significant role in the effectiveness of the procedure and your overall colorectal health.