To determine whether Kristalose causes a significant increase in hydrogen and/or methane gas levels in patients requiring bowel evacuation, and also to determine the safety, efficacy, and patient preference of Kristalose as a bowel evacuant

This is a single center, open-label, pilot study to determine the safety, efficacy, and patient preference of Kristalose as a bowel evacuant prior to colonoscopy. Prior to colonoscopy, subjects will also undergo evaluation for the production of hydrogen and methane gases in the patient's gut (before and after receiving Kristalose) as assessed by a breath analysis instrument. 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).

Inclusion Criteria:

Patients requiring bowel evacuation for colonoscopy

Exclusion Criteria:

1. Patients with galactosemia (galactose-sensitive diet).
2. Patients known to be hypersensitive to any of the components of Kristalose.
3. Patients with possible bowel obstruction, previous colonic surgery, gastric retention, bowel perforation, toxic colitis, toxic megacolon, or ileus.
4. Patients less than 18 years of age.
5. 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.
6. Be pregnant or nursing
7. Be otherwise unsuitable for the study, in the opinion of the Investigator