Fecal transplant (FMT) for C. difficile

Development of the therapy

Stool transfer for intestinal disease is recorded in 4th-century Chinese medicine and was reintroduced into Western practice in 1958 by Eiseman and colleagues for pseudomembranous colitis.¹ Its modern role for recurrent CDI was established by van Nood et al. in a 2013 randomised trial that was stopped early because duodenal infusion of donor faeces was so much more effective than vancomycin (~94% vs 31% cure).² The FDA issued enforcement discretion for FMT in CDI in 2013, and IDSA/SHEA, ACG and AGA guidelines now recommend it after the second or third recurrence.³

Therapeutic target

FMT is not aimed at C. difficile directly. Instead, it re-establishes a diverse community of commensal anaerobes — particularly Bacteroidetes, Lachnospiraceae and Ruminococcaceae — that competitively exclude C. difficile, deconjugate primary bile acids into secondary bile acids that inhibit spore germination, and restore colonisation resistance.⁴

Suggested dosage and route

• Donor stool from a rigorously screened donor (or stool bank) is delivered by colonoscopy, retention enema, nasoenteric tube, or oral capsules.
• A single treatment is curative in roughly 85–90% of patients with multiply recurrent CDI; a second FMT raises the response to >95%.
• Indication: typically considered after ≥2 recurrences (≥3 episodes total) of CDI.

Possible side effects and risks

• Transient diarrhoea, abdominal cramping, bloating, low-grade fever, and constipation in the first 24–48 hours
• Procedure-related risks of colonoscopy or NG-tube placement (bleeding, perforation, aspiration)
• Transmission of pathogens: rare cases of bacteraemia from multidrug-resistant organisms have led to FDA safety alerts and updated donor screening.
• Long-term effects of altering the microbiome remain under study.

FAQ: Who qualifies, and how is it delivered?

Eligibility is always an individual decision between you and your clinical team based on current IDSA/SHEA and ACG guidance.

References

1. Eiseman B, et al. Fecal enema as an adjunct in the treatment of pseudomembranous enterocolitis. Surgery. 1958.
2. van Nood E, et al. Duodenal infusion of donor feces for recurrent Clostridium difficile. NEJM. 2013.
3. Kelly CR, et al. ACG clinical guidelines: prevention, diagnosis, and treatment of C. difficile infections. Am J Gastroenterol. 2021.
4. Khoruts A, Sadowsky MJ. Understanding the mechanisms of faecal microbiota transplantation. Nat Rev Gastroenterol Hepatol. 2016.