Participants at 3 medical centers had same-day VC and OC procedures. Trained radiologists interpreted the VC images. Highly experienced doctors then performed OC. After examining a section of the colon, doctors were told the VC results. If VC identified a polyp that was not seen with OC, the doctors reexamined that section of the colon closely. The researchers then assessed how often the initial OC examination missed polyps that were seen at reexamination after the doctors knew the VC results. They specifically looked for “missed” polyps that were more likely to become cancerous (adenomas > 6 mm).