New Ways to Diagnose Colon Cancer
New advances in colonoscopy promise faster and easier screenings.
Advances in Screening Techniques continued...
However, David Lieberman, MD, says several newly designed scopes are helping
doctors avoid "looping" in a variety of clever ways.
"One innovation is called a variable stiffness instrument -- a scope that
allows the doctor to stiffen the head of the scope, making it easier to get
through the colon and complete the exam," says Lieberman, chief of
gastroenterology at Oregon Health and Science University in Portland.
Additionally, Lieberman tells WebMD that other devices, including one called
NeoGuide, use computer chips to remember the turn of the scope, which, he says,
also reduces the likelihood of looping.
A new device uses balloon technology to push the scope through the colon in
a kinder, gentler way.
"It's a dual balloon system with air between them, and it's actually the air
pressure that gently advances the endoscope through the colon," says Lieberman,
who adds that this too can reduce the possibility of looping.
However, he cautions that many devices are still considered experimental and
not yet proven to work in large clinical trials.
"We are definitely heading in this direction, however, and it's all very
promising," says Lieberman.
Preparing for Success
In order for a colonoscopy to be successful -- at least in terms of getting
a clear visualization -- preparation must include emptying the bowels
completely. Many doctors say that achieving this is tantamount to a quick,
easy, and successful test.
"The single most important way to increase the success of a colonoscopy is
to achieve a good prep. If it's not good, the procedure itself is longer and
more difficult to perform," says Lieberman.
In the past this entailed consuming up to a gallon or more of a powerful
liquid laxative all within a couple of hours, a task that Christie says many
patients found hard to accomplish.
"It's generally not very palatable. Some patients find it very difficult to
consume," says Christie.
Now, however, advances are making the prep easier while helping to ensure
the success of the screening itself.
Among the preps is OsmoPrep, which offers much of the same bowel cleansing
effects as the drink, using half the liquid and no bad taste. The down side:
You have to take a lot of pills in a very short period of time.
According to its manufacturer, Salix Pharmaceuticals, the recommended dosage
is 32 tablets, divided into doses of four tablets every 15 minutes, each taken
with 8 ounces of clear liquid, for a total of 2 quarts. Twenty of the pills are
taken the night before the exam, and 12 the day of the test.
"The hope for the future is a totally prepless exam and we are moving in
that direction," says Lieberman.
Indeed, Lieberman reports that European studies utilizing an MRI are coming
close to achieving this goal.
"With the MRI technology currently being studied in Europe you can
theoretically subtract different densities [of material found in the colon] to
differentiate between fecal matter and a colon abnormality," says
If the European studies turn out well he estimates the prepless colonoscopy
could be a reality within several years.