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

Rice is the staple diet in many Asian countries. Current endoscopic guidelines advice a 6 h fast for solids and a 4 h fast for liquids before the procedure. However, these guidelines focus on a Western type diet. The aim of the study was to determine if a 6 h fast for rice is sufficient prior to upper gastrointestinal endoscopy (UGIE).

After informed consent, 212 patients referred for UGIE, who had no alarm symptoms, were randomized into two groups in preparation for UGIE. Fasting 6 h after a rice meal (R6) or fasting 10 h after a rice meal (R10). All meals contained lentils and an egg, and were isocaloric. Endoscopic vision was graded as poor, average, or good.

In the R10 group (n = 107) vision was poor in 2 (1.9%), average in 7 (6.5%), and good in 98 (91.6%). While in the R6 group (n = 105) vision was poor in 30 (28.6%), average in 19 (18.1%), good in 56 (53.3%). The observed difference of percentages among the two groups for endoscopic vision was significant (M-H Chi-Square for trend = 25.67; df = 1; p < 0.001).

Fasting for 6 h after a rice based meal seems inadequate for UGIE. Fasting for 10 h significantly improves endoscopic vision. Current guidelines need to be re-evaluated for populations where rice is the staple diet.