Colonoscopy outcome is strictly related to the adenoma detection rate (ADR). An endoscopy withdrawal time >6min has been suggested to increase the ADR since it allows for thorough evaluation of the several hidden areas of the colon. The FUSE, full spectrum endoscopy system, has been demonstrated to reduce the rate of missed lesions due to its wide-angle view. In the present study the authors evaluate the impact of WT on ADR for High Definition Standard Endoscopes with just a single imager to the FUSE endoscope.

Introduction Colonoscopy outcome is strictly related to the adenoma detection rate. An endoscopy withdrawal time >6min has been suggested to increase the adenoma detection rate since it allows for accurate evaluation of the several hidden areas of the colon. The FUSE endoscope has been demonstrated also to reduce the rate of missed lesions due to its wide angle view.

Aim of the study to evaluate the impact on the adenoma detection rate either of the use of a FUSE endoscope or of interventions directed at optimizing withdrawal time.

to assess the impact of different factors in influencing the withdrawal time

Methods A prospective non-randomized observational single-center study involving consecutive outpatients, aged 18-85 yr, undergoing colonoscopy with different indications. Previous abdominal colon resection, obstruction, inadequate preparation and incomplete examination were exclusion criteria.

In a 3-month period 4 expert endoscopists will performed 500 colonoscopies either with standard endoscope or with FUSE without a dedicated withdrawal time protocol. Colonoscopy withdrawal times will be measured without the endoscopists' knowledge of being monitored.

During a subsequent 3-month period the same endoscopists will perform further 500 colonoscopies with standard and FUSE scopes using dedicated inspection techniques and a minimum 6-minute withdrawal time. In this second phase withdrawal times will be again measured, but endoscopists will be aware of being monitored.

The following parameters will be recorded:

• Demographic and general characteristics
• Indications to colonoscopy
• Colonoscopy findings
• Quality of preparation: Boston scale
• Time to reach the coecum
• Withdrawal time The adenoma detection rate and the mean adenomas per patients will be calculated.

Inclusion Criteria:

• Indication for colonoscopy, age 18-85

Exclusion Criteria:

• Previous abdominal colon resection, colon obstruction, inadequate preparation and incomplete examination

Adult outpatients undergoing colonoscopy for different indications