The purpose of this study is to determine the efficacy of a split-dose regimen of crystalline lactulose for cleansing of the colon as a preparation for colonoscopy, as assessed by the physician's determination of the cleanliness of the colon using the Boston Bowel Prep Scale (BBPS).

This is a single center, open-label, pilot study to determine the safety, efficacy, and patient preference of a split-dose regimen of Crystalline Lactulose for cleansing of the colon prior to colonoscopy. Safety will be assessed by the occurrence of any treatment emergent adverse events. Efficacy will be determined by the endoscopist's rating of the cleanliness of the colon and the incidence of treatment failure (insufficient evacuation of the bowel). Patient preference will be determined by the patient's responses on a patient questionnaire.

Inclusion Criteria:

• Patients requiring bowel evacuation for colonoscopy

Exclusion Criteria:

• Patients with galactosemia (galactose-sensitive diet)
• Patients known to be hypersensitive to any of the components of Crystalline Lactulose
• Patients with a history of a failed bowel preparation
• Patients with severe constipation, defined as those patients taking daily prescription or over-the-counter laxatives
• Patients with possible bowel obstruction, previous colonic surgery, gastric retention, bowel perforation, toxic colitis, toxic megacolon, or ileus
• Patients on lactulose therapy or receiving any treatment for chronic constipation
• Patients less than 18 years of age
• Inability to understand the requirements of the study or be unwilling to provide written informed consent (as evidenced by signature on an informed consent document approved by an Institutional Review Board [IRB]) and agree to abide by the study restrictions
• Be pregnant or nursing
• Be otherwise unsuitable for the study, in the opinion of the Investigator