TWICE trial

Interventions: Additional forward view examination in the right colon with narrow-band imaging
(Control group)
Standard withdrawal colonoscopy group;
Standard forward view examination in the whole colon with white-light imaging
(Test group)
Second forward view with narrow-band imaging group;
Second forward view examination of the right colon with narrow-band imaging after the first right-colon examination with white-light imaging
Primary outcome(s): Adenoma detection rate in the right colon
Study Design: randomized controlled trial, open(masking not used), active control, parallel assignment, diagnostic purpose