Water Injection Colonoscopy vs Air Insufflation Colonoscopy in Training the Beginners

Water injection colonoscopy has been a generally accepted method in training the beginners of colonoscopy for its low pain and less cecal intubation time, we would conduct this study to investigate more advantages of this method and make most use of it for beginners' training.

Colonoscopy is the gold standard for diagnosing the large bowel diseases, caecum intubation is the success of the colonoscopy, although with the progress of the function and the technique, for most patients, when facing with inexperienced examiners, conventional air insufflation colonoscopy is still a painful experience. Despite of the application of the technique of abdomen compression, position change of the patients and the sedatives or analgesics, to master well of the colonoscopy for the first-learners still needs much practice. 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 effect was notable, but the present researches on water assisted technique has still been confined to following aspects:1.Water infusing was based on air insufflation; predetermined amount of water was infused ,and water was infused while passing through certain segment of the bowel(such as the left half of colon) ; 2.When training the first-learners, certain dose of sedatives or analgesics was injected; 3.The patients recruited were less. Colonoscopies in this study would be performed by in-training examiners, water would be injected completely instead of air insufflation while advancing the colonoscope, the amount of the water infused would not be predetermined but vary from individuals, and all the patients would be examined without any sedatives or analgesics.