Water intubation of the sigmoid colon: water instillation speeds up left-sided colonoscopy

Rapid passage through the sigmoid and descending colon is important during flexible colonoscopy, and colonoscopists have developed several techniques and tricks for achieving this. The present study was designed to explore the effect of instilling 200 ml of water into the first bend of the sigmoid on the speed of passage of the endoscope from the rectum to the left colonic (splenic) flexure.

A prospective study of 100 successive single-handed colonoscopies was carried out, using randomly either the water intubation technique (50 patients) or the traditional method (50 controls) to compare the time needed to pass the endoscope from the rectum to the left colonic flexure.

The results indicate that water intubation allowed the endoscope to be advanced through the sigmoid and descending colon in a median time (fiftieth percentile) of 154.5 seconds, compared to 223.5 seconds using the traditional technique. Water intubation speeds up the insertion time by 31%. This difference was highly significant statistically (P<0.0001). The difference remained significant when the data for men and women were analyzed separately. There was no statistically significant difference in the formation of N loops, or in incidentally formed alpha loops between the two study groups.

The water intubation technique is more efficient than the traditional method, particularly in difficult left-sided colonoscopies, but it is equally safe.