Protocol · Digestive Health
Diarrhea-Predominant IBS (IBS-D) Support Protocol
Peppermint Oil (Enteric-Coated) and Probiotics (IBS-Specific Strains) are the core of this stack, with 6 supporting supplements. Each row gives the amount the protocol lists and the grade our evidence database holds for that supplement in Diarrhea-Predominant IBS (IBS-D) Support.
We are re-verifying the studies cited on protocol pages; only confirmed citations are shown.
The stack
8 supplements · none graded yet
| Grade | Supplement | Amount listed | Why it’s in the stack | Evidence on file | Shop |
|---|---|---|---|---|---|
| Primary stackThe core of this protocol | |||||
| Peppermint Oil (Enteric-Coated) | Amount listed: 180–200 mg enteric-coated capsules 2–3 times daily before meals | Antispasmodic effect relaxes smooth muscle; reduces abdominal pain, bloating, and urgency in IBS | Not graded yet | ||
| Probiotics (IBS-Specific Strains) | Amount listed: Bifidobacterium infantis 35,624, or multi-strain (10–20 billion CFU) daily | Restore gut microbiome balance; reduce visceral hypersensitivity and inflammation; improve gut motility | Not graded yet | ||
| Supporting stackListed as additions to the core | |||||
| Psyllium Fiber (Soluble) | Amount listed: 5–10 g daily in divided doses, start low and increase gradually | Soluble fiber normalizes stool consistency; absorbs excess water in diarrhea-predominant IBS | Not graded yet | ||
| Iberogast (STW 5) | Amount listed: 20 drops (1 mL) three times daily before meals | 9-herb combination with anti-inflammatory, prokinetic, and antispasmodic effects on GI tract | Not graded yet | ||
| L-Glutamine | Amount listed: 5–10 g daily | Primary fuel for intestinal cells; supports gut barrier integrity which may be compromised in IBS-D
| Not graded yet | ||
| Vitamin D | Amount listed: 2,000–4,000 IU daily (target 40–60 ng/mL) | Deficiency common in IBS; supplementation may improve symptoms and quality of life | Not graded yet | ||
| Digestive Enzymes | Amount listed: Broad-spectrum enzyme with meals | May help with incomplete digestion that contributes to symptoms; particularly helpful with FODMAP sensitivity | Not graded yet | ||
| Ginger | Amount listed: 250–500 mg ginger extract 2–3 times daily | Prokinetic and anti-nausea effects; may reduce bloating and improve GI motility | Not graded yet | ||
Shop the evidence-backed picks
The collection holds the supplements we grade A or B for its theme, in third-party tested products where the catalog has them. It opens in our Fullscript store. You can look through it without signing in; Fullscript asks for a free account to order.
Or shop one supplement
Each opens third-party tested products, matched to the dose above where we can.
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How this protocol works
In plain language
Irritable bowel syndrome with diarrhea (IBS-D) is characterized by recurrent abdominal pain associated with bowel movements, along with loose or watery stools. It's a functional GI disorder meaning there's no structural damage, but the gut-brain connection is disrupted, leading to visceral hypersensitivity and altered motility. Triggers include stress, certain foods (especially FODMAPs), gut microbiome imbalances, and sometimes post-infectious changes.
CRITICAL: IBS-D shares symptoms with serious conditions including inflammatory bowel disease, celiac disease, and colorectal cancer. If you have red flags (blood in stool, unexplained weight loss, family history of GI cancer, symptoms starting after age 50, nocturnal symptoms), see a gastroenterologist for proper evaluation. A low-FODMAP diet guided by a dietitian is one of the most effective interventions. These supplements support symptom management but don't replace dietary modification.
Peppermint Oil* (enteric-coated) is the best-studied supplement for IBS. It relaxes the smooth muscle of the intestines, reducing spasms, pain, and urgency. Enteric coating is essential to prevent heartburn and ensure release in the intestines.
Probiotics* help restore balance to the gut microbiome, which is often disrupted in IBS. Bifidobacterium infantis 35624 has the strongest evidence specifically for IBS. Probiotics reduce inflammation, normalize motility, and may reduce visceral hypersensitivity.
Psyllium Fiber* (soluble fiber) is preferred over insoluble fiber in IBS. It normalizes stool consistency - absorbing excess water in IBS-D while also adding bulk. Start slowly to avoid worsening bloating.
Iberogast* is a German herbal combination with good evidence for functional GI disorders. It has multiple mechanisms including anti-inflammatory and antispasmodic effects.
L-Glutamine* is the primary fuel source for intestinal cells. Research shows it can help repair gut barrier dysfunction, which may contribute to IBS-D symptoms.
Vitamin D* deficiency is more common in IBS patients. Studies show supplementation may improve symptoms and quality of life.
Digestive Enzymes* may help if symptoms are triggered by incomplete digestion of certain foods.
Ginger* has prokinetic effects and may help with bloating and nausea.
Expected timeline: Peppermint oil can provide relief within days. Probiotics typically need 4-8 weeks for gut microbiome changes. Dietary modifications (low-FODMAP) often show improvement within 2-4 weeks. L-glutamine for gut barrier: 8-12 weeks.