174 The Effectiveness of Right vs. Left-lateral Starting Position in Unsedated Colonoscopy With Modified-Water Immersion Method Colonoscopy

Abstract

INTRODUCTION: Water immersion (WI) which emphasizes removal of infused water during withdrawal significantly reduced pain and increased willingness to repeat unsedated colonoscopy compared with air insufflation (JIG 2013;3:12). One study in sedated patients with air insufflation colonoscopy method showed that right-lateral (RLP) vs. left-lateral (LLP) starting position improved abdominal discomfort and reduced cecal intubation time (AJG 2015;110:1576). We aim to determine if RLP may reduce the pain score and improve other parameters comparing with LLP in unsedated patients examined with a modified water immersion (m-WI) method which involved episodic water infusion and suction to facilitate insertion. METHODS: Consecutive symptomatic patients meeting the inclusion criteria were consented, enrolled and randomized. Both patients and colonoscopists were unblinded. Patients underwent unsedated colonoscopy with m-WI method with room temperature water. The suction procedure during insertion in this study was not only for fecal debris evacuation but also used as a method to facilitate passage through difficult colonic flexures. We infused the water as needed. The air pump was turned off during insertion. The examinations were performed by PB. The primary outcome of insertion pain was recorded by a visual analogue scale (VAS). We proposed bowel visualization scale (BVS) as shown in Figure 1 to evaluate the interference of fecal debris with cecal intubation rate and time (NCT03489824). RESULTS: Interim analysis was conducted for 105 recruited patients (54 in RLP and 51 in LLP) (74% of sample size). The procedural parameters are shown in Table 1. Changed patient position during colonoscopy showed that fixed position (RLP or LLP) was found in 8 RLP patients and 2 LLP patients; changed only into supine position: 36 patients in RLP and 30 patients in LLP; 3 RLP patients changed into supine then left lateral decubitus and 12 LLP patients changed into supine then right lateral decubitus. Table 1 shows that there was no significant difference between pain score of RLP and LLP. LLP showed faster cecal intubation time in general, in constipation sub group, and also in scale 2 of BVS as shown in Table 2. CONCLUSION: This study support that LLP may a better choice than RLP in performing m-WI colonoscopy examination in unsedated patients. Limitation: The endoscopist (PB) did not have RLP colonoscopy experience before the study was started.