Antispasmodics for pain and cramping
Enteric-coated peppermint oil is one of the better-studied supplements for IBS: pooled trials favor it over placebo for abdominal pain at very low certainty, and the two largest recent trials found no significant difference from placebo on their main measures. Caraway and fennel are traditional antispasmodic and anti-gas herbs with thinner evidence. Read our full peppermint oil evidence review.
Soluble fiber for regularity
Soluble fiber helps both the constipation and diarrhea subtypes by normalizing stool, while insoluble fiber like wheat bran often makes IBS worse. Psyllium has the best evidence; low-FODMAP partially hydrolyzed guar gum is especially gentle.
Probiotics for bloating and the gut-brain axis
Specific probiotic strains can reduce bloating, gas, and overall IBS symptoms. Bifidobacterium infantis 35624 is the most-studied single strain, and Saccharomyces boulardii is useful for the diarrhea subtype.
Gut-lining and digestive support
These are sold for gut-lining and digestive support. L-glutamine's IBS evidence rests mainly on one trial, in adults with post-infectious IBS with diarrhea and a raised permeability test, that we found no repeat of. Read our L-glutamine evidence review.
For constipation-predominant IBS
When constipation dominates (IBS-C), magnesium gently draws water into the bowel to ease passage.
Frequently Asked Questions
What is the best supplement for IBS?
No single supplement is best for everyone. Enteric-coated peppermint oil is one of the better-studied options: pooled trials favor it over placebo for abdominal pain, but the certainty is very low and the two largest recent trials found no significant difference from placebo on their main measures. Beyond that, soluble fiber like psyllium helps regularity, and the probiotic strain Bifidobacterium infantis 35624 reduces bloating and overall symptoms. The best choice depends on your main symptom and IBS subtype.
Does peppermint oil really help IBS?
The evidence is mixed. A 2022 meta-analysis of 10 trials favored enteric-coated peppermint oil capsules over placebo for overall symptoms and abdominal pain but rated the certainty very low, and the two largest recent adult trials found no significant difference from placebo on their main measures. Heartburn is the most common side effect, even with coated capsules.
What fiber is best for IBS?
Soluble fiber, not insoluble. Psyllium is a soluble, gel-forming fiber that improves both the constipation and diarrhea subtypes and has the best evidence, while insoluble fiber like wheat bran often worsens IBS pain and bloating. Low-FODMAP partially hydrolyzed guar gum is especially gentle. Start with a small dose and increase slowly to avoid a temporary gas flare.
Do probiotics help IBS, and which strain?
Certain strains do. Bifidobacterium infantis 35624 is the most-studied single strain for IBS and reduces bloating, gas, and overall symptoms, while Saccharomyces boulardii can help the diarrhea subtype. Benefits are strain-specific, so the strain matters more than the brand. Give a probiotic about four weeks, and stop it if it does not help.
What helps IBS with constipation versus diarrhea?
Match the supplement to the subtype. For constipation (IBS-C), magnesium citrate and soluble fiber like psyllium help move things along. For diarrhea (IBS-D), Saccharomyces boulardii and soluble fiber to firm the stool are more useful. L-glutamine's IBS evidence rests mainly on one trial, in adults with post-infectious IBS-D and a raised permeability test, that we found no repeat of, and the IBS guidelines we checked do not mention it. Peppermint oil and Bifidobacterium infantis 35624 have been studied for pain and bloating across subtypes.
When should I see a doctor about IBS symptoms?
IBS should be diagnosed by a doctor, and you should seek care for alarm features that are not typical of IBS: blood in the stool, unintentional weight loss, fever, anemia, symptoms that wake you at night, a family history of bowel cancer or inflammatory bowel disease, or new symptoms after age 50. These warrant evaluation to rule out other conditions.