The study objectives are to obtain the clinical experience of GR68755 1 mg QD in Japanese female subjects with severe d-IBS who have frequent bowel urgency and to obtain exploratory efficacy and safety data that can be used as reference for endpoints and dosage and administration of a next phase clinical study in Japan.~After giving a written informed consent, subjects will undergo essential observation and examinations during the screening phase and subjects who meet the eligibility criteria will enter into the treatment phase. When subjects enter into the treatment phase, the subjects will administer GR68755 1 mg tablets QD in the morning every day for 28 days from the next day of receiving the investigational products.
This study is an exploratory study aiming (i) to obtain clinical experience of GR68755 in Japanese subjects with severe d-IBS to explore the feasibility of the next phase study and (ii) to obtain reference data for endpoints and dosage and administration of a next phase study.