Colonoscopy is a routinely performed procedure in children and adolescents. Proper visualization of the intestinal mucosa is highly dependent on the quality of the bowel preparation. European Society of Gastrointestinal Endoscopy (ESGE) emphasizes that the timing of bowel preparation is the key factor and recommends that the delay between the last dose of bowel preparation and colonoscopy should be minimized. Timing of bowel preparation prior to colonoscopy has not been studied in children population, yet. The diet regimen before colonoscopy is likely less important than the timing of bowel preparation, however may influence the well-being of children.

Inclusion Criteria:

• Age 6-18 years
• Elective colonoscopy

Exclusion Criteria:

• Chronic renal, liver, or heart failure
• Acute surgical abdominal conditions (e.g., acute obstruction or perforation)
• Acute surgical abdominal conditions (e.g., acute obstruction or perforation)
• Any prior gastrointestinal surgery