Understanding Colonoscopy

Spend thirty minutes. Save your life.

It’s right there on your to-do list: “Make Colonoscopy Appointment.” But you’ve hesitated. The 50th birthday came and went. And perhaps another — or more. Maybe you’re just unsure because you feel healthy. Maybe you’ve lost sight of the fact that colonoscopy protects even healthy people against the serious risk of colorectal cancer. Or, maybe, convincing a loved one of the importance of good colon health is a challenge.

Colon cancer is the second leading cause of cancer deaths.

One of New England’s largest digestive-health practices

Portland Gastroenterology Center is one of New England’s largest digestive health practices and the first gastroenterology practice in Maine with an AAAHC-accredited Endoscopy Center. Our Endoscopy Center is where our team of highly skilled, experienced gastroenterologists perform colonoscopy screenings.

Reported in the New England Journal of Medicine “Journal Watch,” Gastroenterologists Do Colonoscopy Better: Colonoscopy performed by a gastroenterologist was associated with a 65% reduction in risk for colorectal cancer mortality, compared with 57% when performed by a primary care provider and 45% by a surgeon.*

Find out more: watch our video about the importance of colonoscopy screening

Please note that our location has changed since the production of this video. We are located at 161 Marginal Way in Portland.

What exactly is a colonoscopy?

A colonoscopy is a visual examination of the inner lining of the large intestine using a long, flexible, lighted tube with a tiny camera at its tip. Among its other applications in treating colon disorders, a colonoscopy is the most effective way to screen for colon cancer.

Highly preventable.

Simply put, early detection through colonoscopy – the most effective method of screening for colon cancer – can reduce one’s risk of developing the disease by up to 90 percent. “That’s not only because of detection, but also because – and this is very unusual in cancer screening modalities – we can interfere with the natural history of the process,” says Dr. Andreas Stefan of Portland Gastroenterology Center. “More than 95 percent of colorectal cancers develop from polyps, which are removed during colonoscopy, minimizing the risk.”

Ideally, people should begin screenings at age 50, or earlier if there is a family history of colon cancer. (Typically, the average risk of developing colon cancer over an individual lifetime is 6 percent, but this increases if there is any family predisposition.) But despite the clear benefits – and the heightened awareness generated by screenings of celebrities such as Katie Couric and Darryl Strawberry – nationwide, fewer than half the people in the 50-and-over category are coming in for screenings.

“We know that it can be a delicate issue for people, naturally,” Stefan says. “Years ago, people didn’t talk about such medical concerns. But thanks in part to the experiences of some well-known people – Ronald Reagan, John Paul II – the stigma has largely been removed, and the subject becomes more common in everyday, coffee-table conversation.” Whether in such talks, or from their physicians, people are learning that the procedure is, as Stefan puts it, “not a bad test at all. “In fact, the preparation is probably more onerous than the process. That involves colonic evacuation the day before, so the patient will be on a clear-liquid diet, and then drink a purgative the night before, so we are able to view the intestine more effectively.”

Your colonoscopy: what to expect

The American Society for Gastrointestinal Endoscopy has produced a video
on what to expect before, during and after your colonoscopy.
 Click here to view the video.

On the day

On the day, after check-in at our Marginal Way facility’s ambulatory surgery center, the patient changes into a gown, has vital signs taken, has an IV connected and then meets with the physician. “We always speak with the patient beforehand, to go over the medical history and make sure we’re on the same page in regard to comfort levels,” says Stefan. As for the colonoscopy, “Most patients are very comfortable during it, thanks to a light sedative,” Stefan says. “They might experience a few light cramps, but – typically – nothing severe.”

During the procedure – which takes 15-30 minutes of the total 1.5-2 hours of the time the patient is in the office – the physician is aided by a technician and by a nurse, who monitors the patient’s comfort and stability. Portland Gastroenterology Center’s facilities and equipment are state-of-the-art. “Thanks to major advances in technology, scopes have become smaller and more efficient,” says Stefan, who estimates that he has performed more than 12,000 colonoscopies in his medical career.


The colonoscopy is especially effective in that it both screens for and prevents colon cancer through removal of pre-cancerous polyps. Generally, polyps are found in one patient in three, and then eliminated on the spot.

The polyps can be as large as 5 centimeters across, Stefan says, but their removal does not cause pain. “The colon is not sensitive to cutting or burning or cauterizing,” he explains. “There may be some slight cramping or distention, and that’s what the nerve endings will feel. “Sometimes people will have gas after the procedure, when they’re in the recovery room. It’s an unusual place in the universe, where you’re encouraged to pass gas.”

Another important aspect of colonoscopy is that, unlike a mammogram or Pap smear, the screening interval is “anywhere from seven to 10 years,” Stefan says. Also reassuring for patients is the overall treatment provided at Portland Gastroenterology Center. “Our nurses have seen all kinds of anxiety, and they know how to care for people,” Stefan says. “That warmer climate is a big part of the reason patients feel more comfortable at a facility like ours.”

This page includes content from an article written for Portland Gastroenterology Center by Portland Press Herald/Maine Sunday Telegram writers Chris Steward and Peter Weed.

*Defined as general surgeon, colorectal surgeon, abdominal surgeon or surgical oncologist.