Is a six hour fast after a rice meal sufficient before upper gastrointestinal endoscopy?

Abstract

BACKGROUND: Rice is the staple diet in many Asian countries. Current endoscopic guidelines advise a 6 hour fast for solids and a 4 hours fast for liquids before the procedure. These guidelines focus on a western type diet. AIMS: To determine if a six hour fast for rice is sufficient prior to upper gastrointestinal endoscopy. (UGIE). METHODS: In a pilot study using real time ultrasound scanning we found that the time taken for complete gastric emptying after a standard rice meal was 10 hours. After informed consent, 133 patients referred for UGIE without alarm symptoms, were randomised into two groups in preparation for UGIE: fasting 6 hours after a rice meal (R6) or fasting 10 hours after a rice meal (RIO). All meals contained dhal and an egg, and were isocaloric. Endoscopic vision was graded as poor, average or. Good. The endoscopist was not aware of the type of preparation. RESULTS: RIO - vision poor in 1 (1.4%), average in 3 (4.3%), good in 66 (94.3%). R6 - vision poor in 13 (20.6%), average in 10 (15.9%), good in 40 (63.5%). The observed difference of percentages among the two groups for endoscopic vision was significant (Pearson Chi-Square; P<0.001). CONCLUSION: Fasting for 6 hours after a rice based meal seems inadequate for UGIE. Fasting for 10 hours significantly improves endoscopic vision. Current guidelines need to be re-evaluated for the Asian setting.