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Therapeutic Areas: Gastroenterology | Infections and Infectious Diseases | Family Medicine
Disease Category: Irritable Bowel Syndrome (IBS)
Location: United States, GA

Clinical Trial Details


Research Study Summary



A study to assess repeat treatment efficacy and safety of rifaximin 550 mg tid in subjects with irritable bowel syndrome with diarrhea (ibs-d)

Patient Inclusion Criteria:

A subject will be eligible for inclusion in this study if he/she meets all of the following criteria:

  • Subject is ≥ 18 years of age
  • Male or female

Females of childbearing (reproductive) potential must have a negative pregnancy test at Screening/Treatment 1 Phase and agree to use an acceptable method of contraception throughout their participation in the study. Acceptable methods of contraception include double barrier methods (condom with spermicidal jelly or a diaphragm with spermicide), hormonal methods (e. g. oral contraceptives, patches or medroxyprogesterone acetate), or an intrauterine device (IUD) with a documented failure rate of less than 1% per year.

Abstinence or partner(s) with a vasectomy may be considered an acceptable method of contraception at the discretion of the investigator.

NOTE: Females who have been surgically sterilized (e.g, hysterectomy or bilateral tubal ligation) or who are postmenopausal (total cessation of menses for > 1 year) will not be considered "females of childbearing potential."

  1. Subject has IBS confirmed by the Rome III diagnostic criteria (below):
    Recurrent abdominal pain or discomfort at least 3 days per month in the last 3 months, with symptom onset at least 6 months prior to diagnosis associated with 2 or more of the following:
  2. Improvement with defecation
  3. Onset associated with a change in frequency of stool
  4. Onset associated with a change in form (appearance) of stool

**Discomfort means an uncomfortable sensation not described as pain.

  1. During the Screening/Treatment 1 Phase (at least 7 and up to 13 days), the following average daily symptom scores for IBS are required in all categories for entry into the study:
  2. An average score of greater than or equal to 3 for abdominal pain
  3. An average score of greater than or equal to 3 for bloating
  4. At least 2 days in a week with stool consistency of 6 (Fluffy pieces with ragged edges, a mushy stool) or 7 (Watery stool, no solid pieces; entirely liquid) using the BSS

  • Subject had a colonoscopy within the last 2 years that rules out other inflammatory bowel diseases; or, subject will have a colonoscopy within 14 days after signing the informed consent form and 7 days prior to Treatment 1
  • Subject must maintain a stable diet; including dietary supplements, vitamins and other nutraceuticals. Subject should not introduce any major lifestyle changes for the duration of the study (eg.: initiation or discontinuation of a high fiber or low carbohydrate diet)
  • Subject is capable of understanding the requirements of the study, is willing to comply with all study procedures, understands the language of the informed consent form, and is capable and willing to sign the informed consent form

Patient Exclusion Criteria:

A subject will not be eligible for inclusion in this study if he/she meets any of the following criteria:

  • Presents with Type 1 = Separate hard lumps, like nuts (hard to pass) or Type 2 = Sausageshaped but lumpy (on the BSS) during the Screening/Treatment 1 Phase (for entry into Treatment 2 Phase)
  • Subject has failed to record 7 days of the daily diary assessments during the Screening/Treatment 1 Phase (for entry into Treatment 2 Phase)
  • Subject has current evidence of duodenal ulcer, gastric ulcer, diverticulitis, gastroesophageal reflux (GERD), or infectious gastroenteritis. NOTE: Subjects with GERD controlled by stable (> 30 days) doses of medication or diet are eligible to participate in the study
  • Subject has a history of inflammatory bowel disease (e.g., Crohn’s disease, ulcerative colitis, celiac disease), GI malignancy, GI obstruction, gastroparesis, carcinoid syndrome, pancreatitis, amyloidosis, ileus or cholelithiasis
  • Subject has diabetes (Type 1 or Type 2)
  • Subject requires GI surgery, has a history of GI surgery, or has had a polypectomy (open surgical or endoscopic) for which the histology showed it to be malignant. Subjects are excluded if they have had a cholecystectomy and/or abdominal hernia repair less than 6 months prior to signing the ICF. NOTE: The subject is eligible to participate if they have had: a routine endoscopic polypectomy with benign histology, and/or an uncomplicated appendectomy with no history of post operative obstruction or symptomatic adhesions for at least 5 years prior to signing the ICF.
  • Subject has lactose intolerance not controlled by a lactose free diet
  • Subject presents with symptoms of enteric infections including but not limited to Yersinia enterocolitica, Campylobacter jejuni, Salmonella, Shigella, ovum and parasites, and/or Clostridium difficile.
  • Subject has history of a major psychiatric disorder (DSM-III-R or DSM-IV), including major depression, psychoses, alcohol or substance abuse within the past 24 months prior to signing the informed consent
  • Subject has a history of seizure disorders
  • Subject is pregnant, planning to become pregnant, or is lactating
  • Subject has a history of human immunodeficiency virus (HIV) or hepatitis (B or C)
  • Subject has a history of abnormal thyroid function not controlled by thyroid medications
  • Subject has hepatic disease manifested by twice the upper limit of normal (ULN) for any of the following liver function tests: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, or total bilirubin (except in isolated elevation of unconjugated bilirubin)
  • Subject has renal disease manifested by 1.5 times the ULN of serum creatinine or blood urea nitrogen levels
  • Subject has a calculated creatinine clearance level of ≤ 60 mL/min
  • Subject has unstable cardiovascular or pulmonary disease, categorized by a worsening in the disease condition that requires a change in treatment or medical care within 30 days of signing the ICF
  • Subject has any condition or circumstance that adversely affects the subject or could cause noncompliance with treatment or visits
  • Subject has an active malignancy within the last 5 years (exceptions: basal cell carcinomas of the skin, or if female, in situ cervical carcinoma that has been surgically excised)
  • Subject has participated in an investigational study within the 30 days prior to signing the ICF
  • Subject is taking any products specifically marketed as probiotics (standard food or yogurt products are allowed) after initiating diary assessments
  • Subject is taking products or foods containing sugar alcohols (including hydrogenated starch hydrolysates, isomalt, lactitol, maltitol, mannitol, sorbitol (e.g. sugar-free chewing gums or drinks) or xylitol (e.g. sugar-free hard candy, chewing gum, and many processed foods labeled "sugar-free") after initiating diary assessments
  • Subject is taking/has started a course of:
    1. Antidepressants (within 6 weeks of signing the ICF, or if a change in dose or discontinuation of the drug during the course of the study is anticipated).
    2. Anti-seizure and/or antipsychotic drugs (including those for bipolar disorder) within 4 weeks of signing the ICF
  • Subject is currently taking and plans to continue taking antidiarrheals (e.g., loperamide and bismuth subsalicylate) after initiating diary assessments
  • Subject is taking rifaximin or any other antibiotic within 60 days prior to signing the informed consent (ICF)
  • Subject is taking antispasmodics, narcotics, prokinetic drugs, warfarin, lubiprostone, or drugs indicated for IBS (e.g., alosetron) after initiating diary assessments
  • Subject has biopsy proven diagnosis of microscopic colitis

To Learn more



Both Male and Female


18 and up

Overall Status


Facility Type



Columbus Regional Research Institute
800 Talbotton Rd.
Columbus, GA 31904
Phone: 706-321-0495

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Research Center Information: Columbus Regional Research Institute

If you would like to learn more about participating in this research study, please email the trial contact using the form below.

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CW ID: 183042

Date Last Changed: June 27, 2014

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