Investigation of PicoPrep Versus HalfLytely for Bowel Preparation for Colonoscopy - Day Before PicoPrep

Inclusion Criteria: * Male or female, age 18 to 80 years, inclusive, being scheduled to undergo elective colonoscopy * Female patients should be post menopausal (women ≥ 45yrs with no menstrual period for at least 12 months without an alternative medical cause), be surgically sterile, or be using medically approved contraception, throughout the trial period * Females of childbearing potential must undergo a pregnancy test at screening and again at randomization * Subjects must have had more than or equal to 3 spontaneous bowel movements per week for one month prior to the colonoscopy * Subjects should be willing, able and competent to complete the entire procedure and to comply with study instructions * Written informed consent obtained prior to study Exclusion Criteria: * Acute surgical abdominal conditions (e.g. acute obstruction or perforation, etc.) * Active (acute/exacerbation of/severe/uncontrolled) Inflammatory Bowel Disease (IBD) * Any prior colorectal surgery, excluding appendectomy, hemorrhoid surgery or prior endoscopic procedures * Colon disease (history of colonic cancer, toxic megacolon, toxic colitis, idiopathic pseudo-obstruction, hypomotility syndrome) * Ascites * Gastrointestinal disorder (active ulcer, outlet obstruction, retention, gastroparesis, ileus) * Upper gastrointestinal surgery (gastric resection, gastric banding, gastric by-pass) * Uncontrolled angina and/or Myocardial Infarction (MI) within last 3 months, Congestive Heart Failure (CHF), or uncontrolled hypertension * Renal insufficiency (serum creatinine and potassium must be within normal limits) * Participation in an investigational study within 30 days prior to receiving study medication (or within 60 days for investigational drugs with an elimination half-life greater than 15 days) * Any clinically significant laboratory value at the screening, including pre-existing electrolyte abnormality, based on clinical history that the Investigator feels may affect the study evaluation * Hypersensitivity to active ingredients