Relationship of non-polypoid colorectal neoplasms to quality of colonoscopy.

Colonoscopy is a dominant modality for colorectal cancer prevention in average-risk patients aged 50 years and older. Non-polypoid colorectal neoplasms (NP-CRNs) are likely a significant contributing factor to interval colorectal cancers because they have a higher prevalence in Western populations than previously thought, are more difficult to detect visually with conventional colonoscopy, and are more likely to contain advanced histology than polypoid neoplasms, regardless of size. The accurate identification and complete removal of NP-CRNs is thus an integral part of high-quality colonoscopy, and a critical component of the ongoing efforts to make colorectal cancer screening programs widely available, effective, and accepted by patients. In this article, the authors examine the quality indicators for colonoscopy, present the reasons for interval cancers, and discuss the relation between NP-CRNs and quality colonoscopy.