Besides colonoscopy, what other screening methods are there?
Currently, a colonoscopy
is one of the most comprehensive and
reliable screening methods for colon cancer
. While no
method replaces another, the following screening procedures are all tools your healthcare provider could use to
detect the early signs of colon cancer
The technical names for a virtual colonoscopy are computerized topographic
(CT) colonography and magnetic resonance (MR) colonography. These 2
screening procedures are relatively new ways of detecting
and cancer. Similar to a conventional colonoscopy,
the virtual colonoscopy requires the use of a colon prep the day before the
procedure. This cleans the waste from the colon and allows for a clearer view of
the colon wall.
|Courtesy of Viatronix Inc. (www.viatronix.com)
A polyp detected during virtual colonoscopy
At the beginning of the examination, a thin tube is inserted into the rectum to
inflate the colon. The patient is then moved through a large imaging machine.
The machine then produces a computer-generated, 3-dimensional view of the colon.
This procedure has recently been approved by a number of organizations, including the American Cancer Society,
as an accurate way of locating large polyps. However, it may miss some small polyps as well as flat lesions,
which are more likely to become cancerous.
This procedure could identify a polyp, but it does not allow the physician to perform a biopsy or remove a
growth. If a growth is found, the patient would require a conventional colonoscopy to confirm the initial
results and remove the growth.
The virtual colonoscopy is a promising medical development and could be an option for you, but conventional
colonoscopy is still the gold standard of care. At this point, it’s unlikely that a virtual colonoscopy would
be covered by your insurance. Talk to your physician about which procedure is right for you.
This examination is similar to a colonoscopy. The difference is that a sigmoidoscopy only views the lower colon and
the rectum for polyps and cancer. Because the sigmoidoscopy doesn't allow for the examination of the entire colon
it's considered less reliable than a colonoscopy. If a polyp is found during a sigmoidoscopy, a full colonoscopy is
recommended to inspect the rest of the colon.
Fecal occult blood test
One of the symptoms of colon cancer
is blood in the stool. Often the loss of blood is so minimal, it cannot be seen
and a test must be performed to detect the blood. To perform a fecal occult (occult
) blood test, a special card is provided by the healthcare provider, a small amount
of stool is placed on the card and the card is then returned to the healthcare provider or lab. The sample is then
tested for blood that might be hidden. This procedure should be performed yearly for people older than 50 years.
If blood is detected, a colonoscopy is recommended to determine the cause of the bleeding.
Double contrast barium enema (DCBE)
Barium is a liquid that is put into the colon and rectum using an enema (a tube inserted into the rectum). The
barium enables a healthcare provider to see a detailed outline of the colon and rectum in an x-ray. Multiple x-rays
are taken to show the outline of the colon and rectum at different angles. From the outlines, a healthcare provider
may be able to detect the presence of polyps. This screening method has not been shown to be reliable. When polyps
are found, a colonoscopy is normally performed to confirm the results.
Before a colonoscopy or many of these procedures can be done, the bowel must first be thoroughly cleared of all
stool. This process is called a colonoscopy preparation
for short. This is completed prior to the exam, as prescribed by your healthcare provider.
Why do you need a bowel prep?
Learn about OsmoPrep — the colonoscopy prep that’s a pill,
not a liquid.
How can you prevent colon cancer?
What are the symptoms of colon cancer?
Important Safety Information about OsmoPrep
There have been rare, but serious reports of acute phosphate nephropathy in patients who received oral sodium phosphate products for colon cleansing prior
to colonoscopy. Some cases have resulted in permanent impairment of renal function and some patients required long–term dialysis. While some
cases have occurred in patients without identifiable risk factors, patients at increased risk of acute phosphate nephropathy may include those with
increased age, hypovolemia, increased bowel transit time (such as bowel obstruction), active colitis, or baseline kidney disease, and those using
medicines that affect renal perfusion or function (such as diuretics, angiotensin converting enzyme [ACE] inhibitors, angiotensin receptor blockers
[ARBs], and possibly nonsteroidal anti–inflammatory drugs [NSAIDs]).
It is important to use the dose and dosing regimen as recommended (PM/AM split dose).
Please see full Prescribing Information for OsmoPrep, including BOXED WARNING.
OsmoPrep® (sodium phosphate monobasic monohydrate, USP, and sodium phosphate dibasic anhydrous, USP) Tablets are indicated for cleansing
of the colon as a preparation for colonoscopy in adults 18 years of age or older. Considerable caution should be advised before OsmoPrep is used in
patients with severe renal insufficiency, congestive heart failure, ascites, unstable angina, gastric retention, ileus, severe chronic constipation,
bowel perforation, toxic megacolon, gastric bypass or stapling surgery, or hypomotility syndrome. Use with caution in patients with impaired renal
function, patients with a history of seizures or at higher risk of seizure, patients with higher risk of cardiac arrhythmias, known or suspected electrolyte
disturbances (such as dehydration), or people taking drugs that affect electrolyte levels. Patients with electrolyte abnormalities such as
hypernatremia, hyperphosphatemia, hypokalemia, or hypocalcemia should have their electrolytes corrected before treatment with OsmoPrep.
OsmoPrep is contraindicated in patients with a known allergy or hypersensitivity to sodium phosphate salts or any of its ingredients, and in patients with
biopsy–proven acute phosphate nephropathy. In clinical trials, the most commonly reported adverse reactions (reporting frequency >3%) were
abdominal bloating, nausea, abdominal pain, and vomiting. It is recommended that patients receiving OsmoPrep be advised to adequately hydrate before,
during, and after the use of OsmoPrep.