This study is designed to provide information on feasibility and reproducibility of barostat assessments of colorectal sensory functions and compliance and their pharmacological modulation

Inclusion Criteria:

• A positive diagnosis of IBS.
• Subjects must either have been surgically sterilized, hysterectomized at least 6 months prior to screening, be postmenopausal or be using a double-barrier local
• contraception.
• Able to communicate well with the investigator, to understand and comply with the requirements of the study. Understand and sign the written informed consent

Exclusion Criteria:

• History of or evidence for structural diseases/conditions that affect the gastrointestinal system.
• Other diseases or conditions that in the opinion of the Investigator significantly affect colorectal sensitivity.
• Evidence of occult blood at stool analysis, or history of rectal bleeding.
• Using or planning to use drugs or agents during the study period that alter GI physiology and visceral perception.