Aids to insertion: magnetic imaging, variable stiffness, and overtubes.

Inserting the colonoscope quickly and safely without undue patient discomfort is the primary aim of the colonoscopist. The inherently mobile, flexible and unpredictable nature of the colon means that looping occurs frequently during insertion and the colonoscopist must constantly strive to keep the instrument straight whilst at the same time advancing the tip towards the caecum. Colonoscopists have struggled with insertion for many years but recent developments described in this chapter have the potential to make insertion easier and more predictable.