Combination Lubiprostone and Split-Dose PEG-ELS Vs Split-Dose PEG-ELS alone for bowel preparation before colonoscopy in constipated patients: a prospective, endoscopist-blinded, randomized controlled trial

INTERVENTION: Active Comparator Drug,Placebo Comparator Drug split‐dose PEG‐ELS combination with Lubiprostone 3 times ,split‐dose PEG‐ELS combination split‐dose PEG‐ELS combination with Lubiprostone 3 times by specifying as follows; 2 days before colonoscopy 1 capsule of Lubiprostone at 6.00 a.m. then took 1 capsule of Lubiprostone at 6 p.m. Day before colonoscopy ‐ 1 capsule of Lubiprostone at 6.00 a.m. The subjects would receive 1 sachet of PEG‐ELS mixed with 2 liters of water, which the patients had to take all within 2 hours at 6:00 p.m. Lastly, on the colonoscopy day, the subjects received 1 sachet of PEG‐ELS mixed with 2 liters of water and took it all in 2 hours at 4.00 a.m. on the day of the colonoscopy.,split‐dose PEG‐ELS before colonoscopy day, patients had to take 1 sachet of PEG‐ELS with 2 Liter of water at 6 p.m. and 1 sachet of PEG‐ELS with 2 Liter of water at 4 a.m. on the day of the colonoscopy. CONDITION: Colorectal cancer increased incidences in Thailand annually, which was most commonly diagnosed in the advanced stage while less than 50% was diagnosed in stages I and II. Colonoscopy was considered a standard and common‐used method for the screening, diagnosis, and treatment of disease today. Chronic constipation would affect cleansing during bowel preparation. In a foreign study, the preparation of the large intestine in people with constipation showed that the Split‐dose of polyethylene glycol electrolyte lavage solution (PEG‐ELS) could clean the colon around 81.4%. Lubiprostone is a novel medication to increase the amount of fluid within the intestine without severe complications. However, there are limitations to study in Lubiprostone for bowel preparation. ; Colorectal cancer screening; Bowel preparation; Polyethylene glycol electrolyte lavage solution; Lubiprostone; Colorectal cancer screening; Bowel preparation; Polyethylene glycol electrolyte lavage solution; Lubiprostone; PRIMARY OUTCOME: the Ottawa bowel preparation score Colonoscopy day proportion of adequate bowel cleansing SECONDARY OUTCOME: adenoma detection rate Colonoscopy day Number of adenoma,safety profiles Colonoscopy day symptoms,satisfaction Colonoscopy day a questionnaire to assess the satisfaction INCLUSION CRITERIA: 18‐75 years of age patients that are indicated for colonoscopy with constipation (Compatible with ROME IV diagnostic criteria for chronic constipation or history of Bristol stool form scale 1‐2).