Efficacy of Probiotic Bacteria in Subjects With IBS or Functional Diarrhea/ Bloating

Inclusion Criteria: * The subject is 18 to 75 years old. * The subject is an ambulatory outpatient. * The subject has IBS, or functional diarrhea, or functional bloating according to the Rome II criteria for functional GI disorders. * The subject has the above symptoms for at least two weeks, despite current therapy. For diarrhea, we will use the definition of a mean of \>2 bowel movements per day, or a mean score of \> 4 on the Bristol Stool Form Scale per week. For bloating we will use the Rome II definition "a feeling of abdominal fullness or bloating". * Subject must have had a colonoscopy if age \> 50y/o. * The subject's symptoms are mild to moderate symptoms in severity. Symptoms severity will be assessed at baseline and at the end of the 2-weeks screening period to determine eligibility prior randomization. Severity of bowel symptoms will be determined using the Francis Whorwell IBS severity scale: Mild \<175, Moderate 175-300, Severe \>300 Exclusion Criteria: * The subject has inflammation or structural abnormality of the digestive tract (e.g. inflammatory bowel disease (IBD), duodenal ulcer (DU) or gastric ulcer (GU), obstruction, symptomatic cholelithiasis). * The subject has severe FBD related symptoms at baseline. * The subject has a serious, unstable medical condition. * The subject has insulin-dependent Diabetes Mellitus. * The subject had a major psychiatric diagnosis or a suicide attempt within the last two years. * The subject has a history of alcohol or substance abuse within two years. * The subject has abnormal laboratory results (including ALT or AST \> than 2.5 times normal, serum creatinine \>2.0mg/dl, untreated abnormal TSH value) * The subject has been treated for a malignancy within the last 5 years (except BCC or SCC skin cancer). * The subject has been diagnosed with lactase deficiency and this can explain their symptoms (i.e., symptoms resolved or reduced significantly with lactose-free diet.) * The subject has participated in a drug study within the last 21 days. * The subject received antibiotic treatment during the last 8 weeks. (If the subject was on antibiotic treatment, a washout period of 8 weeks is required). * The subject had previous significant intestinal surgery. * The subject is pregnant or lactating, or unwilling to maintain effective contraception during course of study * The subject is predisposed to infection (i.e. their immune system is compromised, they have rheumatic heart disease, an artificial valve, history of bacterial endocarditis, or an active bacterial disease)