Boston Bowel Preparation Scale (BBPS)

The Boston Bowel Preparation Scale (BBPS) is a scale used by a physician who is performing your colonoscopy to judge the quality of bowel cleanliness. It replaces subjective terms such as “excellent”, “good” and “fair”. Three segments of the colon are looked at for this. The highest rating for a segment is 3 so a perfect overall score is 9 = 3 x 3.


  1. Left Colon Quality
  2. Transverse Colon Quality
  3. Right Colon Quality

Each segment is scored as follows:

0 = Unprepared colon segment with mucosa not seen due to solid stool that cannot be cleared.
1 = Portion of mucosa of the colon segment seen, but other areas of the colon segment not well seen due to staining, residual stool and/or opaque liquid.
2 = Minor amount of residual staining, small fragments of stool and/or opaque liquid, but mucosa of colon segment seen well.
3 = Entire mucosa of colon segment seen well with no residual staining, small fragments of stool or opaque liquid.

The physician adds up your scores to arrive at the total BBPS.

Boston Bowel Preparation Scale

Last updated on Dec 10, 2019