Colon Preparation With 2L PEG in Combination With Lubiprostone vs 4L PEG

Colonoscopy is the current standard method for examination of the colon. Bowel cleansing prior to colonoscopy is the essential prerequisite to ensure complete mucosal visualization and lesion identification.(1,2) Suboptimal preparations are associated with missed diagnoses, longer procedure times and increased costs related to the repeat procedures and shortened intervals between procedures.(3-5) Inadequate preparations have been noted in around 25 % cases in the US.(4,6) This has been attributed primarily to poor patient tolerance to the standard colon preparations. Osmotically balanced polyethylene glycol (PEG) electrolyte bowel lavage solutions were introduced in 1980.(7) These PEG based solutions are the most commonly used bowel preparations today.(7) They have high efficacy, are safe and are associated with minimal fluid and electrolyte imbalance. However the major drawback of these preparations is the taste and the large volumes required with associated nausea, cramping and vomiting.(8) This often results in poor compliance and tolerance with resultant poor preparation and improper visualization. A pooled analysis of 15 trials found that at least 29 % of patients were unable to complete their PEG solution.(9) Lubiprostone (LB) is a locally acting selective Type 2 chloride channel activator which causes intestinal fluid secretion. This results in increased softened stool and increased intestinal transit without the loss of either net intravascular fluid or electrolytes.(10) Peak plasma levels occur approximately 1.14 h after oral administration of a single 24 microgram dose, and the half-life of lubiprostone (t½) has been estimated at approximately 3 h.(11,12) LB is currently approved for the treatment of chronic idiopathic constipation and is generally well tolerated with an excellent side effect profile. Even long term usage has not shown clinically significant changes in electrolyte levels.(10,13) Our hypothesis was that administration of LB in addition to low volume (2-L) split-dose PEG would improve the adequacy of the bowel preparation as comparable as standard 4-L split-dose PEG regimens. Additionally, it could improve patient tolerability and decreased side effects related to the large volume of PEG regimens. Accordingly, we conducted this prospective, single-blind, randomized controlled trial.