Randomized placebo-controlled trial of oral liquid simethicone prior to upper gastrointestinal endoscopy

It has been suggested that pre-procedural oral simethicone improves visibility in upper GI tract endoscopy. We examined three-hundred-thirty patients referred for upper endoscopy who were randomized and were required to swallow a placebo solution or one of three liquid simethicone solutions 15 min prior to the examination. These solutions contained 65 mg, 65 mg and 195 mg of drug dissolved in 90 ml, 30 ml and 90 ml of water, respectively. Patients treated with both dosages of simethicone revealed significantly less foam and bubbles in both the stomach and the duodenum compared to placebo. Only the 90 ml volume adequately cleared both locations. The reduction of examination time could be found both in patients with an intact stomach and in patients with or without gastric bile reflux, but was most striking in patients with previous gastric resection (examination time being reduced by almost 50% and the need of adjunctive lavage being reduced about 20 fold compared to placebo). In conclusion, pre-procedural oral simethicone should be routinely considered in patients with previous gastric resection. The utility of the drug is less evident in patients with normal gastric anatomy.