Fasting is the current standard of care for colonoscopies. Recent changes to anesthesia guidelines have allowed for clear fluids to be provided up to 2 hours before procedures, including colonoscopies.

This study will compare fasting to a 12.5% carbohydrate solution 2 hours before colonoscopy on patient-reported measures of discomfort, hydration, and colon visibility.

The investigators hypothesize that the carbohydrate solution will improve patient-reported measures of discomfort, hydration, and colon visibility.

Fasting and bowel preparation before colonoscopy procedures has been the clinical protocol for decades. Evidence suggests that patients undergoing this traditional standard of care before procedures may be associated with common undesirable outcomes, including anxiety, thirst, and poor patient experience. The impacts of fasting and poor satisfaction can create a cascade of challenges regarding communication between clinicians and patients.

The new standard of care utilizes an innovative clear fluid protocol, allowing patients to consume clear fluids up to 2-3 hours prior to their procedure. The consumption of a complex carbohydrate (CHO) drink may reduce dehydration, improve patient-reported outcomes, enhance patient communication and clinician workflow, ultimately resulting in improved patient experience and cancer screening/detection. Although clinical validation and implementation of a complex CHO drink have already been completed in surgical patients within clear fluid protocols, this needs to be expanded to patients undergoing colonoscopy procedures.

A prospective, single-blinded, single-centre, randomized control design will be used to compare fasting from midnight the day of the colonoscopy [the current standard of care] to a clear fluid protocol [a complex CHO drink consumed the night before and 2 hours before the colonoscopy]. The physician performing the colonoscopy will be blinded to the group allocation. The primary outcome of the present study is pre and post-procedure patient-reported measures of discomfort in adults undergoing routine colonoscopy for cancer screening. Secondary outcome measures are compliance, hydration, and bowel visibility.

Hypotheses

1. Patient-reported measures of discomfort pre and post colonoscopy will be lower in patients in the clear fluid group than the standard of care group.
2. Hydration status will be greater in the clear fluids group than the fasting group.
3. Colon visibility score (BBPS) will be higher in the clear fluids group

Inclusion Criteria:

• referred for a routine colonoscopy for cancer screening
• Physician indicates a bowel preparation of split dose 2L PEG ± bisacodyl (iso-osmolar) solution

Exclusion Criteria:

• patients with colonic resection, inflammatory bowel disease; any condition that would preclude colonoscopy of the whole colon;
• patients with lower gastrointestinal bleeding, patients with ileus, gastric retention, intestinal perforation, gastrointestinal obstruction;
• patients with significant heart disease, impaired renal function, decompensated liver disease
• patients who have diabetes
• patients on opioid medications.
• Patients with a corn allergy, or allergy to any ingredient in the complex CHO drink

The principal investigator, clinic staff and outcome assessors of colon visibility and hydration will be blinded to the treatment allocation of participants