Fecal Transplantation for Primary Clostridium Difficile Infection (COLONIZE)

  • End date
    Jan 31, 2024
  • participants needed
  • sponsor
    Oslo University Hospital
Updated on 10 May 2022
antibiotic therapy
fecal microbiota transplantation
clostridium difficile
stool test


In this randomized controlled trial the investigators want to compare the effect of one-time rectal instillation of fecal microbiota transplantation, compared to a ten-day antibiotic course for the treatment of primary Clostridium difficile infection (CDI). The investigators hypothetsize that the instillation of feces from a healthy donor will be non-inferior to vancomycin in inducing a durable cure.


Up to one third of patients with clostridium difficile infection treated with antibiotics experience recurrent or relapsing symptoms within a few weeks. Even with subsequent antibiotic treatment, multiple recurrences/relapses are frequent. Fecal microbiota transplantation (FMT) has been shown to be significantly more effective in curing recurrent CDI than repeated antibiotic treatment. In current guidelines, FMT is proposed as a treatment option after multiple recurrences/relapses of CDI. The rationale to reserve transplantation of donor feces for recurrent and difficult cases of CDI is a possible risk of pathogen transmittance and the process of finding a donor and screen for communicable disease.

The effect of FMT for recurrent CDI, however, suggests that this therapy may be more effective than antibiotics in inducing a durable cure also for primary CDI. If the therapeutic effect of FMT proves to be equal (non-inferior) or more effective than antibiotics, FMT may be the preferable treatment option due to favourable ecological impact compared to antibiotics. In an era with increasing concerns about overuse of antibiotics and emergence of antibiotic resistant bacteria, it is important to investigate therapeutic alternatives that may reduce the need for antibiotics.

This trial is a phase III multicentre, randomized controlled, open-label non-inferiority parallel group trial with two arms (FMT and antibiotics), and is a continuation of the phase II trial IMT for Primary Clostridium Difficile Infection (NCT02301000). In the current trial, patients with Clostridium difficile infection and no previous CDI within 12 months prior to inclusion will be randomized 1:1 to FMT or 10 days of guideline-recommended antibiotic therapy (vancomycin 125 mg four times a day).

Patients are recruited in Norwegian hospitals.

The investigators plan to use frozen microbiota, because supply is easier to organize, compared to fresh fecal samples. Patients in the FMT treatment group will receive one rectal dose of FMT, originating from screened, healthy donors. Patients who are not cured by the first dose is offered a protocol defined additional FMT treatment. In the case of clinical deterioration, appropriate measures will be undertaken according to current guidelines.

Patient treatment outcomes are evaluated after 14, 60 and 365 days from inclusion and treatment initiation.

An interim analysis is planned after inclusion of the first 94 patients (corresponding to 50% of the planned number of patients).

Condition Clostridium Difficile Infection
Treatment Vancomycin, Fecal Microbiota Transplantation
Clinical Study IdentifierNCT03796650
SponsorOslo University Hospital
Last Modified on10 May 2022


Yes No Not Sure

Inclusion Criteria

Patients, ≥18 years with primary C. difficile infection, defined by the following three criteria
Diarrhea as defined by the WHO (≥3 loose stools per day), and
Positive stool test for toxin producing C. difficile, and
No evidence of previous C. difficile infection during 365 days before enrolment
Written informed consent

Exclusion Criteria

Known presence of other stool pathogens known to cause diarrhea
Ongoing antibiotic treatment for other infections that cannot be stopped before study treatment administration
Inflammatory bowel disease or microscopic colitis
< 3 months life expectancy
Serious immunodeficiency, defined as one of the following
Ongoing or recent chemotherapy and current or expected neutropenia with neutrophil count of < 500/μL
Active severe immunocompromising disease
Inability to comply with protocol requirements
Need of intensive care
Known irritable bowel syndrome, diarrheal type
Pregnancy or nursing
Known or suspected toxic megacolon or ileus
Total or subtotal colectomy, ileostomy or colonostomy
Contraindications for rectal catheter insertion
Known hypersensitivity or other contraindications to vancomycin
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