Hydrogen breath test as an indicator of the quality of colonic preparation for colonoscopy

Background. Breath hydrogen levels after ingestion of polyethylene glycol were evaluated as a method of predicting the quality of colonic preparation. Methods: One hundred patients undergoing nonemergency colonoscopy were recruited for this study. After fasting overnight, they were instructed to ingest a polyethylene glycol solution containing 12 g lactulose at a rate of 50 mL every 5 minutes for 2 hours. During ingestion of the polyethylene glycol solution, breath samples were taken at 15-minute intervals for 240 minutes and breath hydrogen concentration was measured. Results: The preparation for colonoscopy was judged to be poor in 18% and adequate in 82%. The breath hydrogen levels over 90 minutes were significantly higher in the poor group than in the adequate group. In all patients with a breath hydrogen level less than 10 parts per million at 240 minutes, the preparation was adequate. Conversely, all patients with a poor preparation had a breath hydrogen level of more than 10 ppm at 240 minutes. Conclusions: The hydrogen breath test effectively predicts adequacy of colonic preparation.