Effectiveness of Enteral Nutrition for Dose Reduction of Low Dose PEG

Comparison of Two Bowel Cleansing Regimens（Controlled Dietary Restriction With Enteral Nutrition and 1.5L Polyethylene Glycol vs Controlled Dietary Restriction and 2.0L Polyethylene Glycol）：an Endoscopist-blinded, Prospective Randomized Controlled Trial

This clinical trial is being conducted to assess whether dietary restriction with enteral nutrition prescribed could prevent nonadherence to dietary restrictions, enable additional reduction of the required volume of PEG-ELS.

Bowel preparation plays a vital role in the quality of colonoscopy.Bowel preparation consists of 2 key steps: dietary restriction and purgative ingestion.Two liters of PEG-ELS are widely used in Asian countries, but in a well-designed clinical trial，additional reduction of PEG-ELS volume seems feasible. Enteral nutrition may simplify the process and avoid unexpected intake of fiber-containing food.

We hypothesized that dietary restriction with enteral nutrition prescribed could prevent nonadherence to dietary restrictions, enable additional reduction of the required volume of PEG-ELS.

Inclusion Criteria:

1. the age of 18-75year
2. Outpatients undergoing colonoscopy
3. Informed consent

Exclusion Criteria:

1. the age >75 years or <18 years
2. history of colectomy or bowel obstruction
3. severe constipation (defined as stool frequerncy of 3 or less/week)
4. current pregnancy or breastfeeding
5. BMI >30, diabetes
6. known allergies to cleansing agents or ingredients of Enteral nutrition
7. inability to follow the oral bowel preparation regimen.