What You Need to Know about a Colonoscopy

March marks National Colorectal Cancer Awareness Month. Nelson Ferreira, M.D., gastroenterologist with Meritus Digestive Health Specialists, explains why this important screening prevents cancer.

Q: What’s colorectal cancer and how common is it?

Dr. Ferreira (DF): Colorectal cancer includes cancers starting in the colon or rectum. Excluding skin cancers, it is the third most common cancer diagnosed in men and women and is the third leading cause of death in the U.S. Colorectal screenings and cancer treatment have greatly improved deaths from colorectal cancer.

Q: Who should get a colonoscopy?

DF: Your chances of developing colorectal cancer increase with age. That’s why patients should begin colorectal screenings starting at age 50. But a father, mother, brother or sister with colon cancer means you probably should be screened sooner depending upon your relative’s age of diagnosis. If you have symptoms such as rectal bleeding, unexplained low blood count and changes in your stool pattern with or without abdominal pain, you should talk to your doctor about a colonoscopy.

Q: Is a colonoscopy my only choice for colorectal cancer screening?

DF: No, but it is the gold standard. A colonoscopy lets the doctor biopsy a lesion or remove any polyps which may have the potential to become cancerous over time.

Other alternatives to the colonoscopy include: a CAT scan or virtual colonography; sigmoidoscopy which examines a third of the colon; or an X-ray known as a barium enema. Tests to determine if there is blood in the stool or the recently developed Cologuard test which looks for colon cancer DNA in the stool are noninvasive; however all of the tests mentioned are less accurate than a colonoscopy, and if positive, will lead to a colonoscopy.

Q: What’s a colonoscopy like?

DF: First, you must drink a laxative prep the day before the procedure and stick to an all liquid diet 24 hours before the screening. You’ll be under sedation while the physician views the entire colon using a flexible tube and tiny camera. Depending on what the physician sees, he or she may or may not remove any precancerous polyps. The procedure typically takes about 20 minutes.

Q: How often do I have to have a colonoscopy?

DF: If the results of your colonoscopy are normal, the exam is repeated every 10 years. If the test detects precancerous polyps, you may require more frequent screenings. Your family history will play a role in colorectal cancer screening.

Q: Who’s at risk for colon cancer?

DF: Certain risk factors can affect your chance of developing colorectal cancer. Risk factors you can’t change include being older, a family history of colorectal cancer, personal history of polyps or having inflammatory bowel disease. Risk factors you can change include weight, smoking, physical inactivity, eating a diet high in red meats and processed meats and heavy alcohol use.

Q: Why do some people avoid a colonoscopy?

DF: It could be the fear of the unknown: “Do I have cancer?” or the procedure sounds too dangerous. Others don’t want to drink the laxative prep to prepare for a colonoscopy and some people don’t have the insurance or the time it takes to undergo the procedure.

Q: What are the signs of colorectal cancer?

DF: Most colorectal cancers begin as polyps and as they grow, they may bleed which can cause blood in your stool. Abdominal or rectal pain, changes in stool size, constipation or diarrhea are also symptoms of colorectal cancer. Low red blood cell counts or anemia is another sign of the disease. However, you can have polyps or cancer and not know it because they don’t always cause symptoms.

Q: What if the doctor finds a polyp. Does that mean I have cancer?

A: A polyp is a benign growth, but over time, some have the potential to turn cancerous. If a physician finds a polyp during a colonoscopy, he or she can remove it safely and completely before it becomes cancerous.

Q: What’s the outlook for someone diagnosed with colon cancer?

DF: If caught early, colon cancer has a 90 percent, five-year survival rate—but many people live a healthy life years after diagnosis. That’s why regular colonoscopy screenings are so important. You can find pre-cancerous growths early before they have a chance to turn into cancer.

Source: American Cancer Society