The bispectral index (BIS) monitoring is an EEG-based method that uses electroencephalogram analysis and a complex algorithm to generate a numerical scoring 0-100 (0 flat line EEG, 100, wide awake) BIS monitoring allows noninvasive, objective measurement of level of consciousness of a sedated patient. A limited number of studies have used measurements of BIS monitoring to assist endoscopic sedation.There are studies using BIS monitoring to make sedation easy for ERCP procedures. However, the studies evaluating use of BIS for gastrointestinal endoscopy show inconsistent results.