Cancelled before active due to the results of emerging scientific data

To better understand the way that GW876008 and GSK561679 work on hormone responses in patients with Irritable Bowel Syndrome.

Inclusion Criteria:

• Has IBS as defined by the Rome II criteria.
• Clinical laboratory tests at screening showing no clinically significant abnormalities in the opinion of the Principal Investigator.
• Non-tobacco user (abstinence from tobacco use for at least 1 month before the start of the study).

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 responsible considers the subject unfit for the study.
• Subject has any of the following exclusionary psychiatric conditions (Note: current diagnoses are to be based on the M.I.N.I administered at screening).
• 1. A current DSM-IV Axis I disorder such as Dysthymia, Phobia, Major Depression, Obsessive Compulsive Disorder, Body Dysmorphic disorder, or Panic Disorder as a primary diagnosis currently or within 6 months prior to the screening visit.
• 2. A current DSM-IV-TR diagnosis of Antisocial or Borderline Personality Disorder, Dementia, or another current DSM-IV-TR Axis II diagnosis that would suggest non-responsiveness to pharmacotherapy or non-compliance with the protocol; or
• 3. A current (within six months prior to Screening Visit) diagnosis of anorexia nervosa or bulimia; or
• 4. A history of Schizophrenia, Schizoaffective Disorder, or a Bipolar Disorder; or
• 5. Is currently being treated by medication for any of the above psychiatric disorders. Psychiatric medications would include, but not limited to, antidepressants (e.g. SSRIs, SNRIs, TCAs) anxiolytics, antipsychotics
• Subjects who, in the investigator's judgement, pose a current, serious or suicidal or homicidal risk or have made a suicide attempt within the past 6 months or have ever been homicidal.
• subjects who have taken any medication for the treatment of IBS within 1 month prior to screening except for anti-diarrhoeal medications or laxatives for control of bowel habit which is allowed if at a stable dose for 2 weeks prior to randomisation.
• Subjects who are taking NSAIDs including aspirin on a regular basis or within 48 hours of a study day.
• Subjects with a history of PUD <10 years ago.
• The subject has a history of, or active eating disorder.