Efficacy Study of Bowel Preparation Before Colonoscopy

Inclusion Criteria: * Men and nonpregnant women who are scheduled for an elective colonoscopy and who are at least 50 years of age. * Are able to communicate with study personnel and comply with study requirements. * Are able and willing to follow study-specified testing, diet, and hydration regimen. * Have been informed of the nature and risks of the study and have given written informed consent. Exclusion Criteria: * Have known or suspected liver disease or any history of abnormal liver function tests. * Have clinically active cardiovascular disease within the past 6 months. * Have blood pressure greater than 150/90 mm Hg. * Have known or suspected renal insufficiency. * Have known or suspected electrolyte abnormalities, gastrointestinal obstruction, gastric retention, bowel perforation, toxic colitis, toxic megacolon, or ileus. * Have a history of prior bowel surgery within 2 years before enrollment, or active inflammatory bowel disease. * Have diabetes or a history of diabetes. * Have clinical evidence of dehydration. * Are pregnant or breast-feeding. * Are unwilling to abstain from alcohol consumption from one day before colonoscopy until discharged from the study. * Use prohibited medications of the study in the defined timeframes. * Have received any investigational agent within 30 days before dosing. * Have any known contraindications to the study treatment. * Have any known or suspected allergies to the components of the study medication. * Have any other condition which would make the subject unsuitable for inclusion in the study.