How many colonoscopies are performed annually in the US?

An estimate given by the Philidelphia Business Journal states:
"Every year, six million people in the United States undergo
colonoscopies, which are used to identify colon cancer."

A link to the full article follows below:
http://philadelphia.bizjournals.com/philadelphia/stories/2004/03/01/story1.html

Thank you for your question,

skermit-ga

While an answer to the question was provided, the answer was a one
line statement in a news article.  No other support was provided to
assure me that the data quoted in the article was, in fact, reliable.

http://www.cnn.com/TRANSCRIPTS/0206/29/smn.05.html
President Bush to Undergo Colonoscopy Today
Aired June 29, 2002 - 07:02   ET 

Two million Americans undergo the procedure every year. That's
actually fewer than should be. Public health authorities for a long
time now have been saying we really need to get more people to get
colonoscopies. And maybe after seeing the president, people will.

http://dceg2.cancer.gov/pdfs/brown1151292003.pdf
Current Capacity for Endoscopic Colorectal Cancer Screening in the
United States: Data from the National Cancer Institute Survey of
Colorectal Cancer Screening Practices

See Table 2. Reported Volume of Endoscopy Procedures by Physician Specialty
Total procedures in the United States
Primary Care 	9100 (0.6)
Gastroenterology 	1,071,000 (66.3)
General Surgery	 535,000 (33.1)

The added information from czh-ga was EXTREMELY helpful.  This answer
and the material provided in the link was substantial evidence to make
me feel comfortable with the data being provided.  Thank you very much
for adding your comment to the previously-supplied answer.