What the label lists and what reports show
Donor human stool side effects
Donor human stool's FDA label: “The most commonly reported (≥ 3%) adverse reactions occurring in adults following a single dose of REBYOTA were abdominal pain, (8.9%), diarrhea (7.2%), abdominal distention (3.9%), flatulence (3.3%), and nausea (3.3%).” FAERS holds 230 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is diarrhoea (83 reports).
- No generic listed
Check it at the source: the donor human stool FDA label on DailyMed (effective December 23, 2024); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsThe most commonly reported (≥ 3%) adverse reactions occurring in adults following a single dose of REBYOTA were abdominal pain, (8.9%), diarrhea (7.2%), abdominal distention (3.9%), flatulence (3.3%), and nausea (3.3%).
Table 1: Adverse Reactions Adverse reactions were defined as solicited and unsolicited adverse events that were assessed as definitely, possibly or probably related to treatment by the study investigator. reported by…
| Adverse Reaction | REBYOTA N=180 n (%) | Placebo N=87 n (%) |
|---|---|---|
| Abdominal Pain | 16 (8.9) | 6 (6.9) |
| Diarrhea | 13 (7.2) | 3 (3.4) |
| Abdominal distension | 7 (3.9) | 2 (2.3) |
| Flatulence | 6 (3.3) | 0 |
| Nausea | 6 (3.3) | 1 (1.1) |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe most commonly reported (≥ 3%) adverse reactions occurring in adults following a single dose of REBYOTA were abdominal pain, (8.9%), diarrhea (7.2%), abdominal distention (3.9%), flatulence (3.3%), and nausea (3.3%). The most commonly reported (≥ 3%) adverse reactions occurring in adults following a single dose of REBYOTA were abdominal pain, (8.9%), diarrhea (7.2%), abdominal distention (3.9%), flatulence (3.3%), and nausea (3.3%) ( Table 1 ). To report SUSPECTED ADVERSE REACTIONS, contact Ferring Pharmaceuticals Inc. at 1-888-FERRING (1-888-337-7464) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. ( 6 ) 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The safety of REBYOTA was evaluated in 2 randomized, double-blind clinical studies (Study 1: NCT03244644 and Study 2: NCT02299570) and 3 open-label clinical studies (NCT01925417, NCT02589847, NCT03931941) conducted in the United States and Canada. …
Source: FDA drug label, Ferring Pharmaceuticals Inc., effective December 23, 2024 (SPL set 7af8a7f6-a441-4dc6-a151-138a89166fbb), via openFDA; the full label on DailyMed
What do FAERS reports show?
230 reports list donor human stool among the medicines taken, each a report of something that happened, not proof the medicine caused it; 6 are coded as a death and 18 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 22 reactions below, 5 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Donor human stool: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions