(WECT) - A colonoscopy may not be as effective as one believed.
A new study shows the traditional colonoscopy is effective in evaluating the left side of the colon, but it may not do so well for the right side.
"The main message is that we need to think hard about what the effectiveness of colonoscopy screening is. It's probably not 90-percent and is more likely to be 60 to 70 percent," said Oncologist Dr. David Ransohoff.
The American College of Physicians say doctors need to advise patients about the limitations of the procedure.
Some things are missed because the colonoscopy eye may simply not see all.
Bowel preparation or the cleansing prior to the scoping may not do as well on the right colon.
"Maybe colon cancer acts differently on the right side than it does on the left side, or progresses more rapidly even if it is the same stage cancer," said surgeon Dr. Brent Christensen.
Christensen said the study begs for more follow up, but also warns about reading too much into the research.
Technology is improving. Some researchers are experimenting with supplemental tools like a laser to throw more light on underlying tissue, while the colonoscopy is in progress.
While virtual colonoscopies look promising, they have limitations for now.
"We don't find polyps with virtual colonoscopy until they are nearly a centimeter in size and that's large enough that some of those are cancers already," said Christensen.
While the traditional colonoscopy may not be what everyone expected, it's still better than not having one at all.
Even the authors of the study admits it still remains a major screening tool to prevent colon cancer.