Condition
Diarrhea Predominant Irritable Bowel Syndrome (IBS-D)
IBS-D is a gut disorder where recurring belly pain comes with loose stools, driven by an oversensitive gut-brain connection and altered gut movement rather than visible damage. The evidence is strongest for enteric-coated peppermint oil, which relaxes gut muscle, and moderate for IBS-specific probiotics. One trial of 121 people found symptom scores fell by about half with a curcumin and fennel oil blend, but fennel's own role is unclear.
Sources: PMID 27308645
- Supplements studied
- 2
- Graded outcomes
- 1
- Trials
- 3
- People studied
- 287
Evidence by supplement
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| IBS Symptom Severity A multicenter RCT of 121 IBS patients found that a curcumin + fennel essential oil combination significantly decreased IBS-SSS scores by ~50% after 30 days vs ~26% for placebo (P<0.001), with 25.9% becoming symptom-free vs 6.8% on placebo. However, fennel essential oil was tested in combination with curcumin, so its independent contribution cannot be isolated. | Improves (the measure goes down) | Moderate effect | 1 study | 121 people | ||
Studies that measured ibs symptom severity | ||||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Immunity | Improves (the measure goes up) | 1 study | 69 people | |||
Studies that measured immunity | ||||||
Key findings
- IBS Symptom SeverityImproves (the measure goes down)
The Diarrhea-Predominant IBS (IBS-D) Support protocol
2 primary supplements · 6 supporting supplements
- Peppermint Oil (Enteric-Coated)180–200 mg enteric-coated capsules 2–3 times daily before meals
- Probiotics (IBS-Specific Strains)Bifidobacterium infantis 35,624, or multi-strain (10–20 billion CFU) daily
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Studies cited
2 studies from PubMed
- Low fermentable oligo-di-mono-saccharides and polyols diet versus general dietary advice in patients with diarrhea-predominant irritable bowel syndrome: A randomized controlled trial
- Low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet compared with traditional dietary advice for diarrhea-predominant irritable bowel syndrome: a parallel-group, randomized controlled trial with analysis of clinical and microbiological factors associated with patient outcomes