Efficacy of 0.5-L vs 1-L polyethylene glycol containing ascorbic acid as additional colon cleansing methods for inadequate bowel preparation as expected by last stool examination before colonoscopy

Table 2 Boston bowel preparation scale

Point(s)	Description
0	Unprepared colon segment with stool that cannot be cleared
1	Portion of mucosa in segment seen after cleaning, but other areas not seen because of retained material
2	Minor residual material after cleaning, but mucosa of segment generally well seen
3	Entire mucosa of segment well seen after cleaning