Is it possible for Colon Cancer to?

Not show up on blood tests, urine tests, X-Ray's and Ultra-Sounds?

The best test possible to detect colon cancer is an
colonoscopy. They go into the intestines with a long tube
like structure, known as a scope and it has a camera
on it. They can see all of the intestinal wall of the Large
intestines.
http://www.gihealth.com/html/test/colono...

To answer your question, yes...it is possible. No test
is 100% accurate. You have to remember that it is
a human looking at a film, not the actual cells of the
intestines that they would see during an colonoscopy.
Human error can cause this to be missed also, it
all depends on who looks at the films and what they know.
Normal standard blood tests would not show this, they
usually check for cancers using other tests like the one
I mentioned.
This here will explain more about colon cancer and
how it is diagnosed and other things:
http://www.gihealth.com/html/education/c...

Colon cancer is usually detected quite easily. Symptoms might include indigestion, and blood in the stool. Detected early, this is a type of cancer that can be cured, so if you have any suspicion that you might have it, consult your doctor immediately!

Colonoscopy is considered the "gold standard" among the recommended tests for colon cancer. Others tests are fecal occult blood test, barium enema and sigmoidoscopy. However, colon cancer may be missed on colonscopy.

http://www.health-screening.sg/colorecta...
http://www.medscape.com/viewarticle/5526...

I had absolutely no symptoms of cancer,
blood tests all ok, no bleeding, no pain, , no blood in stool, change in bowel habits, nothing at all. My wife had cancer, and used her surgeon to have a mole removed. The asurgeon started interrogatinbg mew.., age 50, father had colon cance, I should have a scope job. I relented and agreed to it.
I'm glad I did. No cancer, but 7 polyps which were pre-cancerous.
Yes, the"scope is the only way to be as close to certain as you're going to get.