Oil-lubricated colonoscopy: easier and less painful?

Methods of lubrication are rarely considered to be a matter for study in gastrointestinal endoscopy. We evaluated a new technique, i. e. the release of seed oil in discrete amounts from the tip of the scope during colonoscopy.

346 consecutive patients prospectively underwent colonoscopy with a standard lubricating method (using water-soluble jelly; group A) or with the standard method plus seed oil (corn oil) instillations through the biopsy channel (group B). The following variables were evaluated in the two groups: the success rate for total intubation, and the time required to reach the cecum; the time needed to examine the colon at withdrawal; the detection rates for colorectal diseases; the level of pain and degree of difficulty associated with the examination. Patients in whom total colonoscopy was not achieved were asked to undergo a further examination in which the other lubricating technique was used.

Successful intubation to the cecum was significantly more frequent ( P < 0.005) in the oil lubrication group (group B, 159/168) than in the control group (group A, 145/170), and less time was needed ( P < 0.001). No significant differences were found with regard to time for examination at withdrawal and detection rates for colorectal diseases. Level of pain and degree of difficulty during colonoscopy were significantly lower in the oil group ( P < 0.001). In the cross-over examinations done in patients in whom total colonoscopy was not achieved, no statistical difference was found between the two groups. We observed no side effects for patients or damage to the instrument.

The proposed technique could be a simple, safe, and inexpensive method for easier and less painful colonoscopy; moreover, it might facilitate difficult examinations. Further studies are needed to confirm our data and to ensure that the use of this technique is not liable to damage the scope.