Why You're Still Bloated —
and why the advice you've been given isn't working.

You've cut out gluten. You've tried dairy-free. You've bought the probiotics, taken the digestive enzymes, eaten more slowly, avoided the foods that seem to trigger it. And you're still bloated.

Not occasionally bloated after a big meal. Chronically, persistently, sometimes painfully bloated — in a way that doesn't match what you're eating and doesn't respond the way it should to the things you've tried.

This is one of the most common presentations I see in clinical practice. And the reason those approaches haven't worked is almost always the same: the advice was based on the symptom, not the cause. Bloating is not a diagnosis. It's a signal. And until you identify what's generating the signal, you're managing symptoms rather than resolving anything.

In this post I want to walk you through the six most common drivers of persistent bloating — not as a list of things to try, but as a framework for understanding which one is likely yours and what would actually need to happen to resolve it.

Why the Standard Advice Doesn't Work

The usual guidance for bloating goes something like this: avoid beans, onions, cruciferous vegetables, and fizzy drinks. Try peppermint tea. Walk after meals. Consider a low-FODMAP diet.

These things can reduce symptoms in some people with some types of bloating. But they work by reducing fermentable substrate — essentially starving the bacteria that are fermenting your food and producing gas. They don't address why the bacteria are in the wrong place, why there are too many of them, or why your digestive system isn't clearing them effectively.

For a significant proportion of people with chronic bloating, the problem is not what you're eating. It's what's happening to what you're eating after you swallow it — and that's a biological question, not a dietary one.

The Six Drivers of Persistent Bloating

Low Stomach Acid

This is the one that surprises most people, because the instinct when you feel gassy and uncomfortable after eating is to assume you have too much acid. But chronic bloating is far more commonly associated with insufficient stomach acid than excess.

Stomach acid does more than begin protein digestion — it creates the acidic environment that prevents bacterial overgrowth in the upper digestive tract, signals the release of digestive enzymes and bile downstream, and regulates the speed at which food moves from the stomach into the small intestine. When acid output is low, that entire process begins to break down.

Food sits longer in the stomach. Bacterial populations that should be kept minimal in the upper gut begin to proliferate. By the time food reaches the large intestine, it arrives incompletely broken down — and becomes fuel for excessive fermentation. The gas produced is the bloating you feel.

Long-term use of proton pump inhibitors and H2 blockers, chronic stress, age, and H. pylori infection are all common causes of reduced stomach acid. The GI-MAP stool test measures specific markers that indicate whether stomach acid production is compromised — including H. pylori directly.

Dysbiosis — The Wrong Bacteria in the Wrong Proportions

The gut microbiome consists of trillions of microorganisms whose collective activity has a profound effect on digestion, immunity, mood, metabolism, and inflammation. When the balance between beneficial and harmful species is disrupted — a condition called dysbiosis — the fermentation process that normally occurs in a controlled way in the large intestine can become excessive, unpredictable, and far more uncomfortable.

A 2025 study found that 90.5% of patients with functional abdominal bloating showed significant gut dysbiosis, with reduced levels of beneficial bacteria including Bifidobacterium and Faecalibacterium prausnitzii, and elevated harmful Proteobacteria. This is not a fringe finding — dysbiosis as a driver of bloating is now well-established in the research literature.

The challenge is that dysbiosis is invisible without testing. You cannot identify which species are overgrown, which are deficient, or which pathogenic organisms may be present from symptoms alone. Two people with identical bloating patterns may have completely different microbial pictures — which is precisely why the same probiotic or dietary intervention helps one person and does nothing for another.

"Two people with identical bloating have two completely different microbial pictures. The same probiotic helps one and does nothing for the other. This is why a protocol built from symptoms rather than data produces inconsistent results."

Pathogens Running Undetected

This is the driver that most people — including many practitioners — never consider, because standard stool tests don't look for it.

Blastocystis hominis is a parasitic organism that can colonise the gut and run completely asymptomatically for years while generating chronic low-grade digestive disruption, including bloating, variable bowel habit, and fatigue. I have seen it repeatedly in clients who had no idea it was present — detected only because we ran a comprehensive stool analysis.

H. pylori, the bacterial infection most commonly associated with stomach ulcers, is another. It doesn't always cause obvious symptoms, but it disrupts stomach acid production, impairs gastric motility, and creates exactly the upstream conditions that lead to downstream fermentation and bloating.

Candida overgrowth is a third. Chronically elevated Candida in the gut produces acetaldehyde and other metabolic byproducts that contribute to bloating, brain fog, and fatigue — particularly in people who have had repeated courses of antibiotics.

The GI-MAP test identifies all of these directly using PCR-based DNA analysis — the same technology used in clinical microbiology. Standard NHS stool culture testing does not reliably detect them, which is why they so frequently go unidentified.

Impaired Digestive Enzyme Output

Digestive enzymes are produced by the pancreas and the small intestinal lining and are responsible for breaking down proteins, fats, and carbohydrates into forms the body can absorb. When enzyme output is insufficient, food arrives in the large intestine incompletely digested — and feeds exactly the kind of bacterial fermentation that produces gas and bloating.

Pancreatic elastase is a marker measured on the GI-MAP that directly reflects exocrine pancreatic function. Low levels indicate impaired enzyme output. This is particularly relevant in people whose bloating is accompanied by fatty or loose stools, visible undigested food, or symptoms that worsen with higher-fat meals.

Intestinal Permeability — The Leaky Gut Connection

The gut lining is a single cell layer thick and is designed to act as a selective barrier — allowing nutrients through while keeping bacterial products, partially digested proteins, and toxins out of the bloodstream. When this barrier is compromised, a cascade of effects follows.

The immune system is activated by the inappropriate entry of bacterial lipopolysaccharides (LPS) — fragments of bacterial cell walls. This generates a state of low-grade systemic inflammation. The gut itself becomes more reactive to foods it would normally handle without difficulty. Motility — the rate at which food moves through the digestive tract — is disrupted.

The result is a gut that is simultaneously bloated, unpredictable, and increasingly reactive to a wider range of foods over time. Food sensitivity panels are often elevated not because those foods are genuinely problematic but because the barrier is compromised and the immune system is reacting to proteins that should never have crossed it. Remove the foods but leave the permeability intact, and the problem returns — sometimes with different triggers.

The Gut-Brain Axis and Cortisol

This is the driver that medicine has been slowest to take seriously, despite the fact that the mechanism is now well established.

The gut and brain communicate bidirectionally via the vagus nerve, the enteric nervous system, and the immune and endocrine systems. When the autonomic nervous system is in a state of sustained activation — as it is in chronic stress — the physiological consequences for the gut are direct and significant.

The person doing all the right things dietarily but living in a state of chronic physiological stress will continue to bloat — because the nervous system is running a programme that systematically disrupts every aspect of digestive function. The answer is not another elimination diet. It is addressing the upstream driver.

This is why the DUTCH Plus hormonal assessment — which maps the full cortisol pattern across 24 hours rather than a single blood draw — is part of a comprehensive gut investigation. Chronic bloating and HPA axis dysregulation are frequently found together, and treating one without the other produces incomplete results.

Why Testing Changes Everything

The reason I make the case for testing in the context of bloating is not because it's complicated. It's because the six drivers above require completely different approaches.

Low stomach acid is not treated the same way as Blastocystis infection. Dysbiosis caused by Candida overgrowth requires a different intervention to dysbiosis caused by depleted Bifidobacterium populations. Bloating driven by intestinal permeability responds differently to bloating driven by enzyme insufficiency.

If you don't know which one you're dealing with, you're guessing. And guessing produces inconsistent results, exactly as you have likely experienced.

What I Do Differently

My five-test programme — the Randox blood chemistry panel, GI-MAP stool analysis, DUTCH Plus hormonal assessment, Organic Acids Test, and IgG4 food sensitivity panel — generates over 900 data points across the interconnected systems that determine whether you feel well or you don't.

For someone presenting with chronic bloating, the GI-MAP and DUTCH Plus are almost always the starting point. Together they answer the question that no amount of dietary elimination can answer: what is actually happening in your gut, and what is the physiological environment in which it's happening?

From that picture, a targeted intervention becomes possible. Not a protocol that someone else used. Not a supplement recommended because it helps some people with bloating. A clinical approach based on what your biology is actually doing.