Colonoscopy

What is it?

A colonoscopy is an exam in which a flexible tube with a fiber-optic light and camera (colonoscope) is passed through the rectum along the full length of the colon, also known as the large intestine.

It is done to screen for colorectal cancer, to remove polyps and to diagnose diseases of the bowel such as colitis (inflammatory bowel disease) and diverticulosis. At Hartford Hospital, we do about 5,000 colonoscopy procedures per year.

Why (and When) You Should Get a Colonoscopy

In Connecticut, colorectal cancer is the third-most common cancer diagnosed in women and the fourth-most common cancer diagnosed in men, according to the state Health Department. A colonoscopy is the best-known screening test for colorectal cancer. In fact, doctors can remove polyps during a colonoscopy that can prevent colorectal cancer.

"Early detection of colon polyps and colorectal cancer is essential," says Dr. William Sardella, a Digestive Health Center colorectal surgeon. "Detecting and removing potentially precancerous polyps while they are benign is the ultimate goal of screening. If a malignant polyp or tumor is identified, early diagnosis has a direct impact upon prognosis and simplifies treatment as surgical removal is typically all that is required."

The American Cancer Society, in a 2018 update, says colorectal cancer screening every 10 years should begin at age 45 for people at average risk. However, most guidelines still recommend screening begin at age 50. African Americans and people at increased risk, such as a family history of colon cancer or polyps, may benefit from earlier or more frequent testing.

Here are the current guidelines for people at average risk:

• Regular screening starts at age 50.
• Screening should continue through age 75 for those in good health who have a life expectancy of more than 10 years.
• Between ages 76 and 85, it’s your call. Talk to your doctor, then decide if you want to continue regular screening.
• If you’re over 85, colorectal cancer screening is no longer necessary.

Other Screening Tests for Colorectal Cancer

Although a colonoscopy is the only test that can prevent colorectal cancer, other tests are available to screen for colorectal cancer. If  andy of these tests are abnormal, your provider will recommend a colonoscopy. 

Sigmoidoscopy: Like a colonoscopy, this test uses a flexible lighted tube inserted into the rectum but examines only the lower part of the colon, including the sigmoid colon.  A bowel prep is required. This exam is not considered an adequate screening test, as only the lower portion of the colon is examined. 

Fecal occult blood test (FOBT) and fecal immunochemical test (FIT): A fecal occult blood test looks for blood in your stool, which could be caused by polyps or cancer. FOBT uses guaiac, a plant substance, to coat its test cards. Dietary and medication modifications may be necessary. A FIT is a test performed on a stool sample that detects hidden blood in the stool.  It can be done at home and does not require any change in your diet or medications.

Cologuard: A stool test that detects certain DNA markers and blood in the stool associated with colorectal cancer and advanced polyps. This test, which can be done at home, does not require any changes in your diet or medications. This is not an appropriate screening test for high-risk patients. This includes patients with a personal history of colon polyps, a family history of colon cancer, or symptoms such as bleeding or anemia. 

CT Colonography: A specialized CT scan used to evaluate the lining of the colon.  A bowel prep is required for this test.   If polyps are identified, a colonoscopy will be recommended so they can be removed.

Double-contrast barium enema: If you can’t have a colonoscopy, this enema with barium makes the colon and rectum distinctive under X-rays. Rarely used. 

Your Colonoscopy Procedure

Before the Procedure

Colonoscopy prep has come a long way in recent years. Clearing the bowels the night before the test now requires about half as much liquid intake. 

“We’ve done as much as we can to make this better,” said Dr. Joseph Ianello, a Digestive Health Center gastroenterologist. “Patients do not have to drink the gallon jug of liquid they may remember. The majority of people respond to half-liter preps. We’re working every day to keep the volume low.”

Read more about it here.

• Bowel prep
  Your physician will order a bowel prep regimen that is appropriate for your medical history. It consists of oral laxatives and clear liquids and usually is started the day before the scheduled procedure. You will also be instructed not to eat or drink anything after midnight before your exam. The colon must be completely empty for the exam to accurate and complete. Be sure to follow your doctor's instructions carefully. On occasion, a colonoscopy has had to be rescheduled because of poor bowel prep. If you are passing clear or green liquid with brown flecks prior to the exam, it is a good indication your colon has been adequately cleaned. If this is not the case, you should call your physician's office for further instructions.
• Routine Medications
  

  You should always check with your physician about taking any medication the day of your exam. This includes over-the-counter medications and herbal supplements. If you are taking blood thinners, you may need to stop these medications in coordination with your pcp.  You may need to modify the dose of certain medications (insulin, oral hypoglycemic, blood pressure and cardiac medications) the day of the exam. Please bring a list of ALL medications you take.

Be sure to inform your physician if you require antibiotics before dental or similar procedures. This may also be required before a colonoscopy or endoscopy.

During the Procedure

After registering, you will be brought to a private exam room where a specially trained nurse and your physician will review your medical history, explain the procedure and answer your questions prior to the procedure. An intravenous line that delivers anesthesia will be placed in a vein and your vital signs will be monitored closely.
After you’re placed on your left side and sedated, your doctor will pass the scope slowly along your colon while watching the images on a monitor.

The flexible tube, the colonoscope, passes through your large intestine, allowing your doctor to examine the lining. Air and water are used to slightly inflate the bowel and wash away any residual flecks so that the lining of the intestines can be seen clearly. A sample of tissue (biopsy) may be taken or a polyp may be removed (polypectomy) during this procedure and is painless. The tissue sample will be sent to the pathology lab for evaluation. Results are usually available within a week. The actual procedure usually takes about 30 minutes. Don’t forget, the scope travels about 12 feet – six feet in, six feet out – during the procedure. If polyps are removed, the procedure will last longer.

The colonoscopy rarely causes discomfort.

After the Procedure

You will be brought to a recovery room where your vital signs will be monitored for a brief period and you will be discharged with a family member or a friend. Allow 2-3 hours for the total visit.

You must be discharged with someone who will drive you home and assure your well-being after arriving home. Please arrange to have someone stay with you or be accessible if a problem arises. This is especially important for elderly patients and those with significant medical histories, such as diabetes and cardiac conditions.

If you have been sedated, you will be instructed not to drive or drink alcohol for the rest of the day. Patients are also advised not to do any activities that require mental acuity or physical activity, such as sports, legal decisions, or using power tools. You should rest at home with light activity for the remainder of the day.

In most cases, patients may resume their usual diet immediately. If your doctor advises differently, this will be noted on the discharge instructions.

If you experience any gas discomfort after the exam, this is normal. Air is used to dilate the bowel during the exam. You may use a heating pad or hot water bottle, lie on your left side or walk around to relieve it.

You may resume your usual medications unless indicated on the discharge instructions. If biopsies were done or a polyp removed, your doctor may advise avoiding blood thinners, such as aspirin, Ibuprofen and coumadin for several days to prevent bleeding.

What is Colorectal Cancer?

Colorectal cancer (colon cancer) develops in the colon or rectum. Before a cancer develops, there are often changes in the lining of the intestines. One of these changes is abnormal tissue called a polyp. Although usually benign (not cancerous), a polyp may develop into colon cancer.

Polyps vary in size. Large polyps start at 10 millimeters (less than a half-inch) in diameter. When smaller than 10 millimeters, a polyp’s chance of becoming cancer is a little more than 1 percent. At 20 millimeters (2 centimeters) or larger, it’s 40 percent. 

"Most colorectal cancers start as benign polyps that, over time, turn into cancer," says Dr. Paul Vignati, a Digestive Health Center at Hartford Hospital colon and rectal surgeon. "By removing polyps at the time of colonoscopy, we can reduce the risk of developing colorectal cancer."

All polyps removed during a colonoscopy are sent to a laboratory to determine if they are precancerous, cancerous or not cancerous.

When You’re at Risk for Colorectal Cancer

Here are key factors that can increase the risk of colorectal cancer:

• Age: Simply being over the age of 50 is the most common risk factor for developing colon cancer
• A personal history of colon cancer: People who have had colon cancer are more likely to have a recurrence.
• A personal history of polyps: While most polyps are benign, some may develop into colon cancer.
• A personal history of inflammatory bowel disease: Conditions such as ulcerative colitis and Crohn's disease increase the risk of colon cancer.
• A family history of colon cancer or polyps.
• Familial adenomatous polyposis (FAP), a hereditary condition that creates hundreds of polyps in the colon and rectum.
• A diet high in animal fats from animal sources.
• Physical inactivity.
• Obesity.
• Smoking: Smokers are 30 to 40 percent more likely than non-smokers to die from colorectal cancer.
• Heavy alcohol use.

If you have one or more risk factor, talk to your doctor about the appropriate tests and their frequency.