Abstract

Background/Aims: Simethicone has been effectively used as a preprocedure drink during colonoscopy because it causes bubbles in the lumen to coalesce. We tried to confirm whether simethicone could effectively lessen the bubble formation and shorten the procedure time. In addition, we tried to determine the proper dose of this medication. Methods: Patients were randomized to receive 0 mg as a control group (group I), 200 mg of simethicone at 7 PM in the evening before the procedure (group II), or 200 mg at 7 PM in the evening and 200 mg at 7 AM in the next morning (group III). The bubbles were scored as follows: 0, none or small amounts of bubbles that don't require any jet of water; 1, moderate amounts of bubbles that require two or three jets of water due to the focal distribution; And 2, large amounts of bubbles that require repeated jets (≥4) of water due to the extensive distribution. Results: 101 patients were included in this study. The number of patients in groups I, II and III were 38, 35 and 28, respectively. The procedure time was statistically similar among the three groups. Severe bubbles (score 2) were significantly more likely to occur in group I than in groups II and III (p=0.014). On the other hand, the presence of significant bubbles (≥1) was not different between groups II and III. Conclusions: Simethicone significantly diminished the presence of bubbles. We recommend using 200 mg of simethicone in the evening before the colonoscopy. (Korean J Gastrointest Endosc 2007;34:251⁣255)