This prospective randomized controlled trial compared integrated water jet channel colonoscopy with traditional accessory channel colonoscopy in cecal insertion time among patients undergoing WE method colonoscopy.

When the WE method colonoscopy were done with the accessory channel for both infusing and suctioning of water. The water had to be suctioned or infused alternatively and increaed the insertion time.

With the new designed endoscopy that integrated a separate water jet channel for infusing water, infusing and suctioning of water can be done at the same time. Besides, water jet pumping system could provide a powerful jet to help us open the collapse lumen and keep an appropriate distance between the mucosa and the lens, thus preventing loss of visualization. It will help the colonoscopist to find the way during insertion.

Inclusion Criteria:

• Underwent fully sedative colonoscopy with WE method in the outpatient department

Exclusion Criteria:

• Age < 18 years old or > 80 years old
• Without standard colon preparation
• Allergy to meperidine or propofol
• With a history of partial colectomy
• Refusal to provide written informed consent.

These codes were contained in pre-arranged opaque envelopes, which were opened immediately before insertion of the colonoscope.