Panchromoendoscopy Using Oral Indigo Carmine Mixed With Polyethylene Glycol Prep

Colon cancer occurs in 5% of the US population. Currently colon cancer screening is
recommended at the age of 50 years old for all patients who are at average risk. Colonoscopy
is considered the gold standard test for colon cancer screening. This is partly because
colonoscopy not only can detect polyps which are cancer precursors but also can remove them,
and thereby detecting cancer and its precursors and preventing cancer. Unfortunately recent
data suggest that colonoscopy can miss a significant percentage of polyps, especially on the
right side of the colon. It is thought that one of the major reasons for missing polyps in
the right side of the colon is the fact that they are flat or sessile serrated adenoma, both
of which are more difficult than protruding polyps to identify with ordinary colon
preparation and colonoscopes. Chromoendoscopy is the application of dye during colonoscopy
to enhance detection of polyps. It has been shown that it improves the detection of polyps
and thus has the potential of improving the performance of colonoscopy and increasing the
detection of these difficult to detect polyps. It is however cumbersome and time consuming,
which has discouraged its use. Indigo carmine, one commonly used dye, is actually FDA
approved as a food colorant and can be consumed orally. It is minimally absorbed. In
addition it is used intravenously for diagnosis of injuries of the urinary system because it
is very rapidly excreted by the kidneys. The investigators believe that taking it orally
will be well tolerated, and that any of the dye that is absorbed will be rapidly excreted by
the kidneys and thus quickly eliminated without any side effects. Effective staining of the
colon with indigo carmine and increased detection of polyps could change the current
standard of care for screening for colon cancer.

Inclusion criteria:

Patients presenting for screening or surveillance colonoscopy Must be aged 50 to 75 yrs
Must be able and willing to sign informed consent

Exclusion criteria:

Known Creatinine >1.2

Cirrhosis

Pregnancy or breast feeding

History of anaphylaxis to any dye

History of bowel surgery or small bowel obstruction

History of aspiration

History of dysphagia

American Society of Anesthesia class >2

History of abnormal liver function test in the last year

History of any degree of cytopenia in the last year