In most of situation, left colon (especially SD junction) is considered the most difficult part of colonoscopy, where endoscopist may encounter difficulty for scope insertion and patients may feel pain or uncomfortable. It is suggested more than half of the whole time for scope insertion should be used in left colon. Many methods, such as water immersion, abdominal palpation, have been used to facilitate insertion in left colon. Colonoscopy with whole-colon water exchange method has been shown to be useful for reducing medication used, pain experienced during colonoscopy, increasing the success rate of cecum intubation and adenoma detection rate in sedated and unsedated patients undergoing screening colonoscopy. Exchange of water during scope insertion minimizes loop formation and prevents lengthening and distension of the colon during colonoscopy. This will facilitate the colonoscopy in average or difficult colonoscopy. However, it is not known whether the benefits of water exchange method of colonoscopy was mainly due to its effect on the left colon. We hypothesized that left-colon water exchange colonoscopy (LWE) may have the similar effect regarding the maximal pain score and mean pain score in unsedated patients compared with whole-colon water exchange colonoscopy (WWE). At the mean time, LWE may reduce the insertion time compared with WWE. Here we performed a prospective, randomized controlled study to investigate the efficacies of whole-colon water exchange, left-colon water exchange and air methods of colonoscopy on pain score and insertion time in unsedated outpatients.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SCREENING
Masking
DOUBLE
Enrollment
300
Colonoscopy will be performed with conventional air insufflation during colonoscope insertion.
Water exchange method (The air pump was turned off before colonoscopy. During colonoscope insertion, residual air in lumen was suctioned and 37°C water was infused into lumen to obtain lumen visualization) was used in whole or left colon. Air was insufflated until cecum was reached or appendix opening was seen.
Endoscopic center, Xijing Hospital of Digestive Diseases
Xi’an, Shanxi, China
Cecum intubation time
Insertion time from rectum to reach the cecum.
Time frame: up to three months
Pain scores
Pain scores include mean pain score and maximal pain score. Mean pain score: mean value of patient reported pain score during the insertion phase in three part of colon by using the visual analog pain scale (0=no pain and 10=most severe pain imaginable). Maximal pain score: maximal value of patient reported pain score during the insertion phase in three part of colon by using the visual analog pain scale (0=no pain and 10=most severe pain imaginable).
Time frame: up to two months
Polyp detection rate
The proportion of subjects with at least one polyp.
Time frame: up to six months
Total procedure time
Total time of colonoscopic procedure.
Time frame: up to two months
Cecal intubation rate
Percentage of successful colonoscopy (insertion of colonoscope into cecum).
Time frame: up to two months
Withdrawal time
Withdrawal time is defined as the time from withdrawal of the colonoscope from the cecum to anal verge. (This time is measured independent of any therapeutic maneuvers, such as biopsy or polypectomy.)
Time frame: up to two month
Patients willingness to repeat colonoscopy using same method
When after the colonoscopic examination, patients were asked if they have willingness to repeat the colonoscopy using same method.
Time frame: up to two month
Procedure difficulty evaluated by endoscopist
When after the colonoscopy, endoscopist were asked to score on the difficulty of the colonoscopic procedure. 0-very easy, 10-very difficult
Time frame: up to two month
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