Randomized Placebo Controlled Efficacy And Safety Study Investigating GW876008 In Patients With Irritable Bowel Syndrome

Inclusion Criteria:

- The subject has been diagnosed with IBS consistent with the Rome II Criteria as
adapted in Appendix 3 of the protocol

- The subject has normal results from a flexible sigmoidoscopy, colonoscopy, or a
flexible sigmoidoscopy plus barium enema, according to subject's age, within 5 years
of randomization. Otherwise, the appropriate procedure(s) must be performed and normal
results obtained during the 7-day procedure window (prior to randomization):

If the subject is < 50 years of age and has not had a colonic examination within 5 years of
the Screening Visit, flexible sigmoidoscopy, or colonoscopy must be performed.

If the subject is = 50 years of age and has not had a colonic examination within 5 years of
the Screening Visit, a colonoscopy or flexible sigmoidoscopy plus barium enema must be
performed.

- Colonic procedure results must be known prior to randomization into the study and
dispensing study medication

- During the two-week screening phase, the subject must have conducted self assessments
on = 10 days of 14 day (with 80% compliance on daily IVRS calls) compliance assessment
using the telephone data entry system

Exclusion Criteria:

- As a result of any of the medical interview, physical examination, evaluation of
mental state and psychiatric history or screening investigations the physician

- Subject reported no stool for 7 consecutive days during the two-week screening phase
responsible considers the subject unfit for the study

- The subject has a concurrent illness or disability that may affect the interpretation
of clinical data, or otherwise contraindicates participation in this clinical study
(e.g., an unstable cardiovascular, autoimmune, renal, hepatic, pulmonary, endocrine,
metabolic, gastrointestinal, haematological, or neurological condition).