There is no theoretical or practical reason why non-medical personnel such as nurses could not be trained to perform diagnostic colonoscopy with comparable proficiency as medical endoscopists. Nurse endoscopists have been widely accepted in the United Kingdom for the past 15 years as a valuable resource to cope with the increasing demand for endoscopic service, in particular diagnostic colonoscopy for colorectal screening. A pilot study performed in Hong Kong in 2008 has shown that endoscopy nurses can be trained to perform diagnostic endoscopy safely and reliably. This study aims to demonstrate that properly trained nurse endoscopists have a comparable proficiency in performing colonoscopy procedures as their medical counterparts.

Inclusion Criteria:

• 1. Subjects receiving screening colonoscopy
• 2. Age ≥ 18
• 3. Informed consent

Exclusion Criteria:

• 1. Subjects have undergone colonoscopy in the past 5 years
• 2. Patients with prior colorectal surgery
• 3. Subjects with a personal history of inflammatory bowel disease, colon adenoma or cancer or family history of Familial Adenomatous Polyposis or Familial non-polyposis syndrome
• 4. Pregnant or lactating women
• 5. Lack of consent