Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomized, Double-Blind Study of GT267-004 Versus Vancomycin, and GT267-004 Versus Metronidazole in Patients With C. Difficile-Associated Diarrhea
Brief Summary: Approximately 520 patients will be entered into this study taking place throughout Australia and Europe. This study aims to determine if an investigational drug is safe and effective for treating symptoms of C. difficile-associated diarrhea (CDAD) and lowering the risk of repeat episodes of CDAD. The investigational drug will be evaluated in comparison to current standard antibiotic treatment, so all patients will receive active medication. All study related care is provided including doctor visits, physical exams, laboratory tests, and study medication. The total length of participation is approximately 6 weeks.


Options:
A: Inclusion Criteria:

* 18 years of age and above
* The presence of CDAD at the time of enrollment with no other likely etiology for the diarrhea
* Less than or equal to 48 hours of treatment with metronidazole, vancomycin or other antibacterial therapy specific for CDAD
* Baseline serum potassium \> 3.0 mmol (meq)/L
* Patient considered sufficiently stable clinically to likely complete 6 week study period.
B: Inclusion Criteria:

* Males/females with CDAD
* Females must use adequate contraception
* Signed informed consent

Exclusion Criteria:

* Life-threatening CDAD
* Toxic megacolon
* Pregnant
* Concurrent use of diarrheal agents
* Participation in other trials
C: Inclusion Criteria:

1. Patient \> 18 years of age with diarrhea associated with a positive stool test for C. difficile toxin(s). Patients may be diagnosed with C. difficile by hospital/clinic/reference microbiology laboratory test or by a rapid diagnostic test performed by the study staff and positive test result must be within 14 days of enrollment.
2. Patient must receive standard of care treatment for C. difficile associated disease. Standard of care treatment should include either metronidazole by mouth or intravenously or vancomycin by mouth.
3. Patient or legal representative must have read, understood, and provided written informed consent and Health Insurance Portability and Accountability Act (HIPAA) authorization after the nature of the study has been fully explained.

Exclusion Criteria:

1. History of chronic diarrheal illness such as ulcerative colitis or Crohn's disease.
2. Score of 4 on modified Horn's index
3. Severe C. difficile colitis with planned surgery in less than 24 hours.
4. Positive pregnancy test within 24 hours of study infusion or an unwillingness to undergo pregnancy testing in females of child-bearing potential. Females capable of child-bearing must agree not to become pregnant from the time of study enrollment until at least 3 months after completion of study infusion. If a woman is sexually active and has no history of hysterectomy or tubal ligation, she must agree to use hormonal or barrier birth control with spermicidal gel.
5. Breastfeeding.
6. Receipt of other investigational study agent within previous 30 days.
7. Any other condition that in the opinion of the investigator would jeopardize the safety or rights of the patient participating in the study or make it unlikely the patient could complete the study.
D: Inclusion Criteria:

* Age ≥ 18 years.
* Patients with new onset of disease evidenced by diarrhea (≥ 3 unformed stools within 24 hours), and one or more of the following symptoms of CDAD:

  * abdominal pain or cramps
  * peripheral leukocytosis
  * fever
* C. difficile toxin A or B detected in a stool specimen obtained within 3 days before enrollment by enzyme immunoassay.
* Patients willing to avoid the following medications during the study:

  * oral and intravenous metronidazole
  * oral vancomycin
  * anti-peristaltic drugs
  * opiates (patients on opiates may be included in the study if they were taking opiates prior to enrollment and the dose is not increased during the study)
  * Saccharomyces cerevisiae (baker's yeast)
  * Lactobacillus GG
  * cholestyramine
  * colestipol

Exclusion Criteria:

* Patients with other known causes of diarrhea or colitis (e.g., Shigella, Salmonella, Cryptosporidium parvum, Giardia lamblia, Entamoeba histolytica, inflammatory bowel disease, irritable bowel syndrome, advanced AIDS or chemotherapy for malignancy).
* Patients that commonly have 3 or more stools per day and/or severe abdominal pain in the absence of CDAD.
* Patients with severe lactose intolerance.
* Patients with more than 1 recurrence of CDAD during the 6 months prior to enrollment.
* Patients unable to take oral medications.
* Use within 1 week of enrollment of any drug or therapy with anti-C. difficile activity such as oral or intravenous metronidazole and oral vancomycin. \[Patients that have taken up to 3 doses of metronidazole or vancomycin can be included in the study\].
* Females of child bearing age who are either pregnant, breast-feeding or not using birth control and are sexually active.
* Patients who are either clinically unstable (e.g., fulminant disease patients with signs of toxic megacolon, imminent perforation, colectomy or death) or unlikely to live throughout the 31-day duration of the study due to underlying illness.
* History of hypersensitivity to nitazoxanide or vancomycin or any active ingredient in the formulations.

Answer: A