Bloating has a differential diagnosis, and most of it is not a supplement.

The short version

• In a national survey of 2,510 US adults, 15.9% reported bloating or distension in the previous month, 19.2% of women against 10.5% of men.
• The 2023 AGA clinical practice update advises ruling out carbohydrate enzyme deficiencies by dietary restriction or breath testing, and ruling out coeliac disease by serology with biopsy confirmation, before treating bloating as primary.
• The same AGA update states that probiotics should not be used to treat abdominal bloating and distention.
• In 184 patients with functional diarrhoea or IBS-diarrhoea and no risk factors, 38% tested positive for primary bile acid diarrhoea.
• The positive predictive value of the ovarian cancer symptom index was estimated at 0.6% to 1.1% overall and under 0.5% for early-stage disease, so persistent new bloating warrants an appointment without warranting panic.

A national telephone survey of 2,510 US adults asked what their digestion had done in the previous month. Just over 40% reported at least one symptom. Bloating or distension came in at 15.9% — 19.2% of women and 10.5% of men. More than 65% of respondents rated their symptoms as moderate or severe.

So this is common, and it is not trivial. What it is not is one thing. Bloating is a symptom with a differential, in the same way that a cough is, and the most useful thing we can do here is show you the order a specialist works through it in — because a supplement sits near the bottom of that list, not the top.

The order a specialist actually works in

The American Gastroenterological Association published a clinical practice update on this in 2023. Reading its fifteen best-practice statements as a sequence is more useful than reading them as advice.

• Diagnose primary bloating and distension using the Rome IV criteria — meaning it is a positive diagnosis, not a leftover after everything else fails.
• Rule out carbohydrate enzyme deficiencies with dietary restriction and/or breath testing.
• Rule out coeliac disease with serology; if the serology is positive, confirm it with a small bowel biopsy.
• In a small subset of at-risk patients, evaluate for small intestinal bacterial overgrowth with small bowel aspiration or glucose- or lactulose-based hydrogen breath testing.
• Order abdominal imaging and upper endoscopy only where there are alarm features, recent worsening, or an abnormal physical examination.
• Do not order gastric emptying studies routinely.
• If the bloating looks tied to constipation or difficult evacuation, do anorectal physiology testing to rule out a pelvic floor disorder.

Notice what sits at the top of that list. Two of the first things to exclude are a carbohydrate you cannot digest and coeliac disease, and both are found with a test rather than with a trial-and-error shopping trip.

The three patterns that point somewhere specific

It follows a food, reliably, within an hour or two. That is the enzyme and fermentation lane — lactose, fructose, sorbitol, the FODMAP family. It is the one pattern where an elimination protocol earns its keep, and the low-FODMAP diet is the structured way to test it rather than guess.

You are also not emptying properly. Chronic constipation is one of the most under-recognised causes of visible distension, and the AGA update says outright that medications used to treat constipation should be considered for bloating when constipation symptoms are present. If evacuation itself is difficult — straining, incomplete emptying, needing to help — that is a pelvic floor question, and biofeedback rather than fibre is the treatment that matches it.

Your stools are loose and urgent. Then the thing to ask about is bile acid diarrhoea. In 184 patients with no risk factors who met criteria for IBS-diarrhoea or functional diarrhoea, 38% tested positive for primary bile acid diarrhoea. It is common, it is testable, and it is treated by binding bile rather than by adding anything.

The one we are not going to be casual about

Persistent, daily, new-onset bloating in a woman is on the ovarian cancer symptom list, and we would rather say that plainly than let you find it at 2am.

Here is the honest arithmetic alongside it. In 812 women with ovarian cancer and 1,313 population controls, the positive predictive value of the symptom index was estimated at 0.6% to 1.1% overall, and under 0.5% for early-stage disease. The authors' own conclusion was that using symptoms to trigger evaluation would find the disease in about one in a hundred women in the general population who have them.

One in a hundred is small. It is also not zero, and the test is a conversation and an ultrasound. Bloating that is new, daily, does not fluctuate across the day or the month, or arrives with weight loss, bleeding or a persistent change in bowel habit, is a GP appointment. Not a purchase.

Where supplements honestly sit

We sell a probiotic with the word UNBLOAT on it, so let us be the ones to tell you this. Best practice advice 10 in that AGA update reads: probiotics should not be used to treat abdominal bloating and distention.

We are not going to argue with it, and we are not going to hide it either. Probiotics have far better evidence for global IBS symptoms than for distension specifically, and if your problem is the visible swelling itself, the AGA's judgement is that the evidence does not support a probiotic as the treatment for it. What the same document does support for bloating is dietary work with a dietitian, treating any constipation, biofeedback for a pelvic floor disorder, and brain-gut behavioural therapies including hypnotherapy and diaphragmatic breathing.

If what you actually have is IBS rather than isolated distension, the shelf gets slightly better: peppermint oil is the one thing in the aisle with a meta-analysis behind it, and probiotics have a real if strain-dependent effect.

And no, none of this is leaky gut. That phrase is doing a lot of commercial work at the moment, and the science underneath it does not say what the marketing does.

What we would tell you to do first

Keep two weeks of notes: what you ate, when the swelling started, how long it lasted, what your stools were doing. It costs nothing and it decides which of the lanes above you are in, which is the actual question. Then take those notes to a GP rather than to a search bar — because the two causes the specialists exclude first, a carbohydrate you cannot digest and coeliac disease, are both settled with a test.

Good questions

What should I get tested for before buying anything for bloating?

Coeliac serology and a carbohydrate malabsorption assessment. The 2023 AGA clinical practice update puts both near the top of the workup: coeliac disease is found with a blood test and confirmed with a small bowel biopsy, and carbohydrate enzyme deficiencies are found with dietary restriction or breath testing. Both are common, both are treatable, and neither is found by trying supplements in sequence.

Do probiotics help bloating?

For distension specifically, the AGA says no. Its 2023 update states plainly that probiotics should not be used to treat abdominal bloating and distention. We sell one, and we would rather print that than bury it. Probiotics have better evidence for global IBS symptoms than for visible swelling, so the honest question is which of those two problems you actually have.

Could my bloating be ovarian cancer?

It is unlikely, and it is still worth checking. In a study of 812 women with ovarian cancer and 1,313 controls, the symptom index had a positive predictive value of 0.6% to 1.1%, roughly one in a hundred. That is small, but the check is a conversation and a scan. New, daily bloating that does not fluctuate, or bloating with weight loss or bleeding, is a GP appointment.

Why do I look pregnant by the evening but fine in the morning?

That daily rhythm is characteristic of functional bloating rather than a structural problem, and it usually means gas load, constipation and abdominal wall coordination are interacting across the day. It is worth telling a clinician about, because a pattern that resets overnight points somewhere quite different from swelling that never resets.

Is bloating a sign of a bad microbiome?

Not reliably, and the phrase does more selling than explaining. Bloating has a differential that includes constipation, pelvic floor dysfunction, carbohydrate malabsorption, coeliac disease, bile acid diarrhoea and visceral hypersensitivity. Most of those are diagnosed with a test, and none of them is fixed by a general microbiome product. Find the lane first.

How long should I keep a food and symptom diary?

Two weeks is enough. Record what you ate, when the swelling started, how long it lasted, and what your stools did. Most people find a pattern they had filed as random, and the pattern is what decides whether your next step is a breath test, a coeliac panel, a constipation treatment or a dietitian. It costs nothing, which is more than can be said for guessing.

Sources

1. Sandler RS, Stewart WF, Liberman JN, Ricci JA, Zorich NL. Abdominal pain, bloating, and diarrhea in the United States: prevalence and impact. Dig Dis Sci, 2000. View study
2. Moshiree B, Drossman D, Shaukat A. AGA Clinical Practice Update on Evaluation and Management of Belching, Abdominal Bloating, and Distention: Expert Review. Gastroenterology, 2023. View study
3. Shiha MG, Ashgar Z, Fraser EM, Kurien M, Aziz I. High prevalence of primary bile acid diarrhoea in patients with functional diarrhoea and irritable bowel syndrome-diarrhoea, based on Rome III and Rome IV criteria. EClinicalMedicine, 2020. View study
4. Rossing MA, Wicklund KG, Cushing-Haugen KL, Weiss NS. Predictive value of symptoms for early detection of ovarian cancer. J Natl Cancer Inst, 2010. View study
5. Ingrosso MR, Ianiro G, Nee J, Lembo AJ, Moayyedi P, Black CJ, Ford AC. Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome. Aliment Pharmacol Ther, 2022. View study

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.