Warm water or oil-assisted colonoscopy: toward simpler examinations?

Completion rates, pain, and difficulties during the exam are still problems in colonoscopy. New methods of lubrication, rarely considered a matter of study, may help in this respect. Our aim was to compare an oil-assisted technique with a modified warm water method applied during colonoscopy.

A prospective, randomized, and controlled study was planned in which three groups of patients were submitted to colonoscopy: a standard lubricating method (water-soluble jelly: group A, 170 patients) was adopted in a control group, whereas the standard method plus injection into the colon of corn seed oil (group B, 170 patients) or warm water (group C, 170 patients) were employed in the other groups. The main variables evaluated were: the success rate for total intubation, the time required to reach the cecum and the time needed to examine the colon at withdrawal, and the level of pain and degree of difficulty associated with the examination.

Successful intubation to the cecum was significantly more frequent (P < 0.01 and P < 0.001, respectively) in the oil group (group B, 155/166) and in the warm water group (group C, 156/163) than in the control group (group A, 138/164), and less time was needed (P < 0.001); no significant difference was found between group B and C. Furthermore, no significant differences were found with regard to time for examination at withdrawal among the three groups. Level of pain and degree of difficulty during colonoscopy were significantly lower in the oil (P < 0.001) and in the warm water (P < 0.001) groups than in the control group, but no significant difference was found between group B and C. Neither side effects were observed for patients nor damage to the instrument.

Warm water and oil-assisted colonoscopy could be simple, safe, and inexpensive methods for easier and less painful examinations.