The purpose of this study is to determine the efficacy and safety of different doses of SKI3246 compared with placebo in the treatment of patients with irritable bowel syndrome with non-constipation.

Inclusion Criteria:

• Have been diagnosed as non-constipation by ROME III.
• Patients who voluntarily signed written informed consent may participate in the study.

Exclusion Criteria:

• Pregnant or lactating female.
• Patients with a history of inflammatory bowel disease.
• Severe neurological or psychological disease
• History of allergic reaction to the medications used in this study
• Use of other investigational drugs within 30 days prior to the study.
• Patients that investigators consider ineligible for this study