Warm water infusion versus air insufflation for unsedated colonoscopy: a randomized, controlled trial.Radaelli F, Paggi S, Amato A, Terruzzi V. Gastrointest Endosc. 2010 Oct;72(4):701-9. BACKGROUND: Uncontrolled data suggest that warm water infusion (WWI) instead of air insufflation (AI) during the insertion phase of unsedated colonoscopy improves patient tolerance and satisfaction. OBJECTIVE: We tested the hypothesis that water could increase the proportion of patients able to complete unsedated colonoscopy and improve patient tolerance compared with the conventional procedure. DESIGN: Randomized, controlled trial. SETTING: Single center, community hospital. PATIENTS: Consecutive outpatients agreeing to start colonoscopy without premedication. METHODS: Patients were randomly assigned to either WWI or AI insertion phase of colonoscopy. Sedation and/or analgesia were administered on patient request if significant pain or discomfort occurred. MAIN OUTCOME MEASUREMENTS: Percentage of patients requiring sedation/analgesia. Pain and tolerance scores were assessed at discharge by using a 100-mm visual analog scale. RESULTS: A total of 230 subjects (116 in the WWI group and 114 in the AI group) were enrolled. Intention-to-treat analysis showed that the proportion of patients requesting sedation/analgesia during the procedure (main outcome measurement) was 12.9% in the WWI group and 21.9% in AI group (P = .07). Cecal intubation rates were 94% in the WWI group and 95.6% in the AI group (P = .57). Median (interquartile range) scores for pain were 28 (12-44) and 39 (14-54) in WWI and AI groups, respectively (P = .05); corresponding figures for tolerance were 10 (3-18) and 14 (5-42), respectively (P = .01). The adenoma detection rates were 25% and 40.1% for the WWI and AI groups, respectively (P = .013). LIMITATIONS: Single-center study, endoscopists not blinded to randomization. CONCLUSIONS: WWI instead of AI is not associated with a statistically significant decrease in the number of patients requiring on-demand sedation, although it significantly improves the overall patient tolerance of colonoscopy. The finding of a lower adenoma detection rate in the WWI group calls for further evaluations.