A Placebo-Controlled Trial of St. John's Wort for Irritable Bowel Syndrome
Condition: Irritable Bowel Syndrome
MeSH terms: Irritable Bowel Syndrome; Syndrome
Intervention: St. John's wort; Placebo
Intervention description: Dosage form: Tablet (450 mg) Dose: 450 mg twice a day, placebo twice a day; Dosage form: Tablet (450 mg) Dose: 450 mg twice a day, placebo twice a day
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Enrollment: 70.0
Sex: All
Minimum age: 18 Years
Maximum age: 70 Years
Healthy volunteers: No

Summary:

      This study is being done to see if St. John's wort helps people with irritable bowel
      syndrome, otherwise known as "IBS". St. John's wort is a herbal supplement derived from the
      St. John's wort plant. It has been shown to be helpful in several medical conditions such as
      depression as well as other pain syndromes.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Established diagnosis of IBS

          -  Meet Rome II diagnostic criteria for IBS

          -  18-70 years of age

          -  U.S. resident

          -  English-speaking (able to provide consent and complete questionnaires)

          -  Able to participate in all aspects of the study

        Exclusion Criteria:

          -  Known alternative/concurrent gastrointestinal diagnosis (e.g. Crohn's disease,
             ulcerative colitis, microscopic colitis, celiac sprue, chronic pancreatitis or
             pancreatic insufficiency, scleroderma, chronic intestinal pseudo-obstruction,
             bacterial overgrowth, recent (<6 months) intestinal bacterial/protozoal/ parasitic
             infections, HIV, fecal incontinence, small bowel or colonic resection, pelvic floor
             dysfunction, paraplegia or quadriplegia)

          -  Current symptoms of severe depression, as measured by Center for Epidemiological
             Studies Depression Scale (CES-D) score

          -  Mental retardation or any condition requiring a legal guardian

          -  Current or past history of psychotic disorder (schizophrenia, bipolar disorder)

          -  Recent or current use (within past 30 days) of select mood or pain or symptom-altering
             medications:

               -  benzodiazepine use

               -  substance abuse

               -  narcotic use

               -  antihistamine use

               -  barbiturates

               -  zaleplon (Sonata)

          -  Recent or current use (within past 30 days) of drugs that interact with SJW:

               -  antidepressants or antipsychotics

               -  tramadol (Ultram)

               -  sumatriptan (Imitrex)

               -  digoxin (Lanoxin)

               -  anticonvulsants (e.g. carbamazepine or phenytoin)

               -  immunosuppressants: cyclosporine and tacrolimus

               -  HIV protease inhibitors (e.g. indinavir), non-nucleoside reverse transcriptase
                  inhibitors (e.g. nevirapine)

               -  warfarin (Coumadin)

               -  theophylline

               -  chemotherapy

               -  sulfa-containing drugs

               -  piroxicam (Feldene)

               -  simvastatin (Zocor)

               -  sibutramine (Meridia)

               -  verapamil (Calan or Isoptin)

          -  Planned surgery (especially transplant) or anesthesia exposure during trial

          -  Known photosensitivity or planned photodiagnostic or phototherapy procedures

          -  Are pregnant, lactating, likely to become pregnant during medication phase and not
             willing to use a reliable form of contraception (barrier contraceptives, diaphragm,
             injections, intrauterine device, surgical sterilization, and abstinence)

          -  Recent or current use (within 30 days) of SJW, other herbal products for IBS,
             investigational drug use

          -  Known allergy to SJW

          -  Significant acute or chronic progressive neurologic, hepatic, renal, cardiovascular,
             respiratory or metabolic disease

          -  Recent history of alcohol or substance dependence use or abuse

          -  Another household member or relative participating in the study

          -  Professional drivers or operators of heavy machinery

          -  Major cardiovascular events in the last 6 months

          -  Use of IBS-specific drugs such as tegaserod (Zelnorm) and Lotronex (Alosetron) (within
             30 days)