This will be a single-center, randomized, parallel group, multiple dose administration, double-blind, placebo-controlled study to evaluate the effects of YKP10811 on gastric, small bowel, and colonic transit in patients with Chronic Constipation or Functional Constipation. Four groups including a placebo group will be enrolled and will receive multiple oral doses of YKP10811 or matching placebo.

If the participant fulfills the initial eligibility criteria, the patient will be randomized to 1 of the active treatment groups or placebo. During the treatment period, patients will receive study medication once daily for 8 days. Patients will undergo scintigraphic assessment of gastric, small bowel and colonic transit of solids over the 48-hour period.

Patients will be males or females, 18 through 65 years of age with a body mass index (BMI) of 19 through 40 kg/m2, with Chronic Constipation or Functional Constipation and no evidence of evacuation disorder as assessed by the Investigator and meet all the inclusion criteria and none of the exclusion criteria.

Inclusion Criteria:

1. Non-smokers (refrained from any tobacco or nicotine usage, including smokeless tobacco, nicotine patches, etc.) for at least 6 months prior to Day 1 of the study
2. Body Mass Index of 19 through 40 kg/m2
3. Participants must be willing to follow dietary restrictions
4. Females of childbearing potential (ie, not menopausal, no hysterectomy, no bilateral oophorectomy) must complete a negative pregnancy test (urine) prior to receiving any radioisotopes
5. No evidence of pelvic floor dysfunction
6. If clinically indicated, absence of an evacuation disorder should be confirmed within 30 days prior to the first dose of study medication
7. At Screening, patients must meet ROME III Criteria for FC, which assumes an absence of a structural or biochemical explanation
8. The patient's screening (baseline) colonic transit test must show a GC ≤ 2.4 at 24 hours; and
9. Baseline EKG shows QTc interval ≤ 450mSec

Exclusion Criteria:

1. History of clinically-significant manifestations or current abnormality of any organ system
2. History of inflammatory bowel disease
3. Any history of GI surgery within 6 months prior to the first dose of study medication
4. History of clinically-significant prolonged diarrhea, in the absence of a laxative
5. Patients who have started a special dietary habit and/or an intense physical workout program within 4 weeks prior to the first dose of study medication
6. Any clinically-significant surgical procedure within 30 days prior to the first dose of study medication
7. History of alcoholism or drug addiction within 12 months prior to the first dose of study medication
8. Any patient who has had an acute illness within 5 days prior to the first dose of study medication, eg, flu syndrome, GI virus, indigestion
9. Patients who are breastfeeding