The investigators aim is to study the efficacy of mentholyptus drops in improving the palatability of PEG-electrolyte solution used in bowel cleansing for colonoscopy. The study is a randomized controlled trial which will include patients undergoing elective colonoscopy at the American University of Beirut Medical Center. Patients will be randomized into one of two study arms using a computer generated randomization list. Patients assigned to the intervention arm will be asked to have candy (Halls®) during the whole 2 hours period while drinking the PEG solution unlike the control arm patients who will only receive the PEG solution. All patients will then be evaluated for the tolerability of the preparation while taking into account the palatability of the solution as main outcome and the remaining volume of the PEG solution and side effects as secondary outcomes.

Inclusion Criteria:

• elective colonoscopy
• consent to the study

Exclusion Criteria:

• pregnant or lactating women
• age less than 18 years
• significant gastroparesis
• gastric outlet obstruction
• ileus
• known or suspected bowel obstruction or perforation
• phenylketonuria
• glucose-6-phosphate dehydrogenase deficiency
• severe chronic renal failure (creatinine clearance <30 mL/minute)
• severe congestive heart failure (NYHA class III or IV)
• dehydration
• severe acute inflammatory disease
• compromised swallowing reflex or mental status
• uncontrolled hypertension (systolic blood pressure ≥170 mm Hg, diastolic blood pressure ≥100 mm Hg)
• toxic colitis or megacolon
• previous colonoscopy within the last 5 years
• active Inflammatory bowel disease
• previous colectomy or partial colectomy