This is a randomized, parallel, multi-center, single-blind study, comparing BLI-800 to an FDA approved bowel preparation in adult subjects undergoing colonoscopy.

Inclusion Criteria:

-Male or female outpatients who are undergoing colonoscopy for a routinely accepted indication, including:

Evaluation of BE results GI bleeding Anemia of unknown etiology Neoplastic disease surveillance Endosonography Inflammatory bowel disease Unknown diarrhea or constipation etiology Polypectomy Laser therapy Routine Screening

• At least 18 years of age
• Otherwise in good health, as determined by physical exam and medical history
• If female, and of child-bearing potential, is using an acceptable form of birth control (hormonal birth control, IUD, double-barrier method, depot contraceptive, abstinent, or vasectomized spouse)
• Negative urine pregnancy test at screening, if applicable
• In the Investigator's judgment, subject is mentally competent to provide informed consent to participate in the study

Exclusion Criteria:

• Subjects with known or suspected ileus, severe ulcerative colitis, gastrointestinal obstruction, gastric retention, bowel perforation, toxic colitis, or megacolon.
• Subjects with impaired consciousness that predisposes them to pulmonary aspiration.
• Subjects who are undergoing colonoscopy for foreign body removal and decompression.
• Subjects with clinically significant electrolyte abnormalities based on Visit 1 laboratory results, such as hypernatremia, hyponatremia, hyperphosphatemia, hypokalemia, hypocalcemia, dehydration, or those secondary to the use of diuretics or angiotensin converting enzyme (ACE) inhibitors.
• Subjects with a history of renal or hepatic insufficiency or congestive heart failure.
• Subjects who had previous gastrointestinal surgeries
• Subjects who are pregnant or lactating, or intending to become pregnant during the study.
• Subjects of childbearing potential who refuse a pregnancy test.
• Subjects who are allergic to any preparation components
• Subjects who, in the opinion of the Investigator, should not be included in the study for any reason, including inability to follow study procedures.
• Subjects who have participated in an investigational clinical, surgical, drug, or device study within the past 30 days.