Lubiprostone Plus Polyethylene Glycol-electrolyte Solutionvs. Placebo Plus Polyethylene Glycol-electrolyte Solution for Outpatient Colonoscopy Preparation: A Randomized, Double-blind, Placebo-controlled Trial
Lubiprostone Plus Polyethylene Glycol-electrolyte Solutionvs. Placebo Plus Polyethylene Glycol-electrolyte Solution for Outpatient Colonoscopy Preparation: A Randomized, Double-blind, Placebo-controlled Trial
The primary objective is to compare the effectiveness and tolerance of the medication named lubiprostone plus a large volume liquid laxative versus placebo which is a look alike medication that has no effect such as a sugar pill plus a large volume liquid laxative as a bowel cleaning preparation for colonoscopy to see the colon better during the colonoscopy to identify abnormal growths such as polyps or colon cancer.
Colonoscopy is considered the best way to screen for colon cancer screening because you can visualize the colon directly and remove or biopsy abnormal growths. The limiting step in the procedure is the quality of the colon preparation prior to the procedure. Many patients do not tolerate large volumes of liquid used to prepare the colon. The purpose of the study is to improve the quality of the prep by adding a pill laxative medication before starting the large volume laxative to better see the colon. The other aim of the study is to try to reduce the amount of of liquid laxative the patient has to drink by giving a pill laxative before starting the liquid laxative.
The study is a double blind placebo controlled study of lubiprostone in 4 doses vs look alike placebo in 4 doses before bowel preparation for outpatient screening, surveillance and diagnostic colonoscopy. Patients with severe underlying medical conditions were excluded. Patients with inflammatory bowel disease, frequent bowel movements and colonic resection were also excluded. Patients were randomized to one of two groups. The study was double blinded. The first group took lubiprostone 24 micrograms and the second group took look alike placebo in 4 divided doses right before starting the bowel prep with the last dose upon starting polyethylene glycol-electrolyte solution the evening before the colonoscopy.
All study patients were educated and instructed to observe for clear stool, which was defined as "watery consistency without any solid fecal material or dark liquid stools" before stopping the liquid bowel prep. Patients were instructed to return the unused PEG solution on the day of colonoscopy. After completing the preparation but before colonoscopy, patients were also required to fill a questionnaire to assess the tolerability of tablets and solution. This was measured on a 1-5 rating Likert scale (1) "Easy," 2) "Tolerable," 3) "Slightly Difficult," 4) "Extremely Difficult," and 5)"Unable to Finish" and was based on the patient's ability to swallow the liquid and each of 4 tablets. In addition, the pres- ence of symptoms of nausea, vomiting, abdominal pain, chest pain, dizziness, and bloating was evaluated.
The primary endpoints was the endoscopist's evaluation of the preparation quality. All colonoscopies were performed by 3 endoscopists (with 85% of the procedures performed by principal investigator of the study, A.L.S.). Endo- scopists evaluated the quality of the colonoscopy prep- aration based on the previously validated Ottawa bowel preparation scale.5 This scale rates 3 sections of colon, rectosigmoid, mid, and right colon, on a 5-point scale (0-4) and a global 3-point rating (0-2) for overall colonic fluid. The total score ranges from 0-14; score of 0 being perfect and score of 14 indicating solid stool in each colon segment and lot of fluid.The secondary endpoint was to determine any reduction in the amount of PEG consumed in the lubiprostone group compared with the placebo group.
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Exclusion Criteria: