The Microbiome Brief
Delivery method

Poop pills: fecal transplant in capsule form

“Poop pills” — the name patients actually search for — are oral capsules containing processed, screened donor stool or defined bacterial spores. They deliver the same principle as a conventional fecal transplant without a colonoscopy, and one capsule product is now FDA-approved in the United States.

What a poop pill actually is

Two broad types exist. Research capsules contain filtered, freeze-dried (lyophilised) donor stool in acid-resistant capsules that release in the lower intestine rather than the stomach. Manufactured products — currently Vowst in the US — contain a standardised preparation of purified Firmicutes spores made under pharmaceutical regulation, so every dose is identical and rigorously screened.1

Advantages over colonoscopy and enema delivery

  • No procedure: swallowed at home or in clinic — no bowel prep sedation, scope, or day-case admission.
  • Repeatable: capsules make multi-dose or maintenance courses practical, which matters in conditions like ulcerative colitis where single doses rarely hold.
  • Shelf-stable: freeze-dried capsules can be stored and shipped, unlike fresh stool preparations.
  • Patient preference: surveys consistently find patients prefer capsules when efficacy is equivalent.2
  • Comparable outcomes in CDI: trials of oral capsule FMT for recurrent C. difficile show cure rates in the same range (~80–90%) as colonoscopic delivery.3

The trade-offs: capsules bypass the stomach but not always the small bowel, some conditions respond better to lower-tract delivery, and dozens of capsules may be needed per course.

What poop pills cost

  • Vowst (US, FDA-approved): roughly $17,500 list price for a four-day course, typically taken after antibiotics for recurrent C. difficile. Insurance coverage — including Medicare Part D — varies, and the manufacturer runs copay assistance programmes.
  • Research/clinic capsules: where offered off-label by specialist clinics, costs commonly run from a few hundred to several thousand dollars depending on screening and monitoring; insurance rarely pays outside approved indications.
  • UK: no capsule product is NHS-funded at present; NICE-recommended FMT for recurrent C. difficile is usually delivered by colonoscopy, enema, or nasogastric tube within hospital services.

See the full cost & insurance page for how these figures compare with clinic-delivered FMT and Rebyota.

Where capsule FMT is being studied

Beyond C. difficile, capsules are the dominant delivery method in ongoing trials for ulcerative colitis, IBS, depression, and metabolic disease — largely because they make placebo-controlled, double-blind studies possible. Notably, capsule trials have also produced some of the strongest placebo responses, which is one reason results outside CDI remain hard to interpret.

FAQ: poop pills

References

  1. Khanna S, et al. Oral, spore-based fecal microbiota live-brpk (Vowst/SER-109) for prevention of recurrent C. difficile infection. N Engl J Med. 2022.
  2. Kao D, et al. Effect of oral capsule- vs colonoscopy-delivered fecal microbiota transplantation on recurrent Clostridium difficile infection: a randomized clinical trial. JAMA. 2017.
  3. Youngster I, et al. Oral, frozen fecal microbiota transplant capsules for relapsing Clostridium difficile infection. BMC Medicine. 2016.