The Bristol stool form scale ( BSFS) based tailored bowel cleansing regimen might be helpful to improve bowel cleansing quality before colonoscopy.

Colonoscopy is the standard approach for evaluating the colon currently. Thorough bowel cleansing is critical for adequate visualization of colonic mucosa during colonoscopy. Inadequate bowel cleansing results in adverse consequences for the examination, including lower adenoma detection rates, longer procedural time, lower cecal intubation rates, shorter intervals between examinations and an estimated 12-22% increase in overall colonoscopy cost.Unfortunately, despite advances in bowel preparation methods, up to one-third of all colonoscopies are reported to have an inadequate bowel preparation.

The Bristol stool form scale ( BSFS) was developed in 1988 by O'Donnell LJD et al and was widely applied in both gastrointestinal study and clinical practice. BSFS divides human stool into 7 different styles according to its moisture content. In our clinical work, we find that it is prone to gain poor bowel cleansing quality in patients who pass type 1or 2 stool. Unfortunately, there is lacking of study on tailored bowel preparation according to Bristol stool form scale. Thus, we intend to develop an easy, practical, BSFS based tailored bowel cleansing regimen, in order to serve clinical work and research.

Inclusion Criteria:

• Patients 18 years of age or older,
• scheduled to undergo elective outpatient colonoscopy,
• and were able to provide informed consent.

Exclusion Criteria:

• history of colorectal surgery
• severe colonic stricture or obstructing tumour
• dysphagia
• compromised swallowing reflex or mental status
• significant gastroparesis or gastric outlet obstruction
• known or suspected bowel obstruction or perforation
• severe chronic renal failure (creatinine clearance<30 ml/min
• severe congestive heart failure (New York Heart Association class III or IV)
• uncontrolled hypertension (systolic blood pressure>170 mm Hg, diastolic blood pressure>100 mm Hg)
• inflammatory bowel disease or megacolon
• dehydration
• disturbance of electrolytes
• pregnancy or lactation
• haemodynamically unstable
• unable to give informed consent.