"Air Assisted"Water Injection Colonoscopy in Experienced Endoscopists

"Air Assisted"Water Injection Colonoscopy in Experienced Endoscopists

Up to now, many studies has showed that compared with air insufflation colonoscopy, water-related colonoscopy could shorten the cecal intubation time and relieve the pain of the patients,especially for training the beginners,the investigators conduct this study to preform the "air assisted" water injection colonoscopy in experienced endoscopists.

In order to further develop water skills and apply the water assisted colonoscopy technique more flexibly, the investigators designed this study.

Inclusion Criteria:

• Patients diagnostic colonoscopy;
• Subjets able to provide informed consent

Exclusion Criteria:

• Prior partial or complete colectomy;
• Patients who decline to participate;
• Patients with poor bowel preparation;
• Contraindications of the colonoscopy