To compare the safety and efficacy of BLI-801 administered at 4 dose levels in constipated adults.

Inclusion Criteria:

• Male or female subjects at least 18 years of age
• Constipated according to ROME I criteria
• 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, sterilized, 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, gastrointestinal obstruction, gastric retention, bowel perforation, toxic colitis, toxic megacolon
• Subjects taking laxatives or prokinetic agents that refuse to discontinue these treatments for the duration of the study
• 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 BLI-801 component.
• 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