What the label lists and what reports show
Donor human stool spores side effects
Donor human stool spores's FDA label: “The most common adverse reactions (reported in ≥5% of participants) were abdominal distension (31.1%), fatigue (22.2%), constipation (14.4%), chills (11.1%), and diarrhea (10.0%).” FAERS holds 1,163 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 (549 reports).
- No generic listed
Check it at the source: the donor human stool spores FDA label on DailyMed (effective April 23, 2026); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of VOWST?The most common side effects observed in patients taking VOWST were: bloated abdomen fatigue constipation chills diarrhea These are not all the possible side effects of VOWST. Be sure to tell your healthcare provider about any side effect that bothers you or that does not go away. For more information, ask your healthcare provider or pharmacist. Call your healthcare provider for medical advice about side effects. You may report side effects to Aimmune Therapeutics, Inc. at 1-833-246-2566 or FDA at 1-800-FDA-1088 or report online to www.fda.gov/medwatch.
Source: FDA drug label, Aimmune Therapeutics, Inc., effective April 23, 2026 (SPL set 99e5a37a-930c-4641-bcdd-7013ec1c15fe), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (reported in ≥5% of participants) were abdominal distension (31.1%), fatigue (22.2%), constipation (14.4%), chills (11.1%), and diarrhea (10.0%).
Table 1: Adverse Reactions Reported in ≥5% of VOWST-treated Participants and at a Frequency Greater than Placebo within 8 weeks after receipt of VOWST or placebo (Study 1) Safety population, defined as all randomized…
| Adverse Reaction | VOWST N=90 % | Placebo N=92 % |
|---|---|---|
| Abdominal distension | 31.1 | 29.3 |
| Fatigue | 22.2 | 21.7 |
| Constipation | 14.4 | 10.9 |
| Chills | 11.1 | 7.6 |
| Diarrhea | 10.0 | 4.3 |
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 common adverse reactions (reported in ≥5% of participants) were abdominal distension (31.1%), fatigue (22.2%), constipation (14.4%), chills (11.1%), and diarrhea (10.0%). Most common adverse reactions (reported in ≥5% of participants) were abdominal distension (31.1%), fatigue (22.2%), constipation (14.4%), chills (11.1%) and diarrhea (10.0%). ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Aimmune Therapeutics, Inc. at 1-833-246-2566 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 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 VOWST was evaluated in one Phase 3, randomized, double-blind clinical study (Study 1: NCT03183128) and one Phase 3, open-label clinical study (Study 2: NCT03183141) conducted in the United States and Canada. Adults with confirmed rCDI were required to have symptoms controlled 48 to 96 hours post-antibacterial treatment to be eligible for enrollment and randomization (1:1) to receive either VOWST or placebo (capsules containing 92 ± 4% glycerol in saline) for 3 consecutive days. …
Source: FDA drug label, Aimmune Therapeutics, Inc., effective April 23, 2026 (SPL set 99e5a37a-930c-4641-bcdd-7013ec1c15fe), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,163 reports list donor human stool spores among the medicines taken, each a report of something that happened, not proof the medicine caused it; 13 are coded as a death and 97 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 23 reactions below, 7 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.
Reports received each year
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 spores: 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