A Placebo-Controlled Trial of St. John's Wort for Irritable Bowel Syndrome

• Bowel Symptom Score (BSS) Amongst Subgroups [ Time Frame: 12 weeks ]
  Median (average) BSS amongst the different IBS subgroups (diarrhea, constipation, pain, and bloating). The BSS is a 100-mm visual analog scale for the different symptoms of IBS (pain/discomfort, constipation, diarrhea, and overall severity). Symptoms on the BSS can range from 0 = no pain to 100 = extreme pain.
• Adequate Relief ≤ 50% During the Last 4 Weeks of Therapy [ Time Frame: Last 4 weeks of therapy ]
  Participants who reported "yes" or "no" to having adequate relief of their IBS symptoms at least 50% during the last 4 weeks of therapy.
• Irritable Bowel Syndrome - Quality of Life (IBS-QoL) Score [ Time Frame: 12 weeks of treatment ]
  The IBS-QOL is a self-report quality-of-life measure specific to Irritable Bowel Syndrome (IBS) that can be used to assess the impact of IBS and its treatment. The IBS-QOL was measured at baseline, week 12 and week 24. The individual responses to the 34 items are summed and averaged for a total score and then transformed to a 0-100 scale for ease of interpretation with higher scores indicating better IBS specific quality of life.
• Center for Epidemiologic Studies Depression Scale (CES-D) Score [ Time Frame: 12 weeks ]
  We measured CES-D Score at baseline as well as bi-weekly throughout the study. The CES-D is a self-reported 20 question survey designed to measure depressive symptomatology in the general population. The possible range of scores is zero to 60, with the higher scores indicating the presence of more symptomatology.
• IBS Symptoms Moderately or a Lot Better [ Time Frame: 24 weeks ]
  Number of participants who stated their IBS symptoms were moderately better or a lot better at 24 weeks.
• Center for Epidemiologic Studies Depression Scale (CES-D) Score [ Time Frame: 24 weeks ]
  We measured CES-D Score at baseline as well as bi-weekly throughout the study. The CES-D is a self-reported 20 question survey designed to measure depressive symptomatology in the general population. The possible range of scores is zero to 60, with the higher scores indicating the presence of more symptomatology.
• Bowel Symptom Score (BSS) at 24 Weeks [ Time Frame: 24 weeks ]
  The BSS is a five question, 100-mm visual analog scale of four IBS symptoms (pain/discomfort, bloating, constipation, and diarrhea), and an overall severity scale. The best possible value would be 0 (no symptoms) and the worst is 500 (severe symptoms). BSS was assessed on a bi-weekly basis.

• Adequate relief of IBS symptoms at least 50% of the last 4 weeks of therapy [ Time Frame: 12-24 weeks ]
• Overall and individual BSS scores at 12 & 24 weeks [ Time Frame: 12-24 weeks ]
• Adequate relief of IBS symptoms at 24 weeks [ Time Frame: 12-24 weeks ]
• IBS health-related quality of life scores at 12 weeks [ Time Frame: 12-24 weeks ]

Eligibility criteria:

1. Established diagnosis of IBS
2. 18-70 years of age

4) U.S. resident 5) English-speaking (able to provide consent and complete questionnaires) 6) Able to participate in all aspects of the study

You will be asked to do the following:

• Undergo a screening interview and physical examination
• Take a urine pregnancy test (if applicable)
• Take a study pill twice daily for 12 weeks(3 months)
• Complete daily symptom diaries and bi-weekly questionnaires for 12 weeks.
• Complete a questionnaire at 6 months after the active phase of the study is over.

• Drug: St. John's wort
  Dosage form: Tablet (450 mg) Dose: 450 mg twice a day, placebo twice a day
  Other Names:

  • Latin name: Hypericum perforatum L.
  • Common name: St. John's Wort
• Drug: Placebo
  Dosage form: Tablet (450 mg) Dose: 450 mg twice a day, placebo twice a day

• Placebo Comparator: Placebo
  Intervention: Drug: Placebo
• Active Comparator: St. John's Wort
  Intervention: Drug: St. John's wort

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)