Why Is My Stomach Always Bloated? 9 Root Causes Functional Medicine Looks For
Feeling bloated occasionally after a large meal is normal. Feeling bloated every day is not something you should have to accept as just your digestion.
Stomach bloating can feel like pressure, fullness, trapped gas, abdominal swelling, tight clothing around the waist, or looking visibly distended by the end of the day. For some people, bloating appears right after eating. For others, it builds slowly throughout the day and is worst at night.
The frustrating part is that bloating is not one single condition. It is a symptom. In functional medicine, we ask a deeper question: what is causing the gut to produce, trap, react to, or fail to move gas and fluid properly?
At Wave Functional Health, we look at bloating through a root-cause lens, assessing digestion, motility, microbiome balance, inflammation, food reactions, hormones, stress physiology, and nutrient status.
Is It Bloating, Distension, or Both?
People often use bloating and distension interchangeably, but they are slightly different.
Bloating is the sensation of internal pressure, fullness, or trapped gas. Distension means the abdomen visibly expands. You can feel bloated without visible swelling, and you can have visible distension without much pain. Some people also become more sensitive to normal amounts of intestinal gas, meaning the issue may involve the gut-brain axis, not just too much gas.
9 Common Reasons Your Stomach Is Always Bloated
Constipation or Slow Gut Motility
One of the most overlooked causes of bloating is not gas production but poor gas clearance. If stool is moving slowly, gas becomes trapped behind it. Bloating from constipation often worsens throughout the day and may improve after a complete bowel movement. Common contributors include dehydration, low thyroid function, poor bile flow, nervous system stress, and mineral imbalance.
Food Intolerances and Fermentable Carbohydrates
Certain carbohydrates are more fermentable, meaning gut bacteria break them down and produce gas. These include foods high in FODMAPs such as onions, garlic, wheat, beans, apples, pears, some dairy products, and certain sweeteners. If your gut ecosystem is inflamed, constipated, or overgrown with bacteria in the wrong location, these foods can trigger significant bloating.
Small Intestinal Bacterial Overgrowth (SIBO)
SIBO occurs when excess bacteria grow in the small intestine and ferment carbohydrates too early in the digestive process, producing hydrogen, methane, or hydrogen sulphide gas. SIBO bloating often appears quickly after eating, especially after carbohydrates, starches, fruit, fibre, prebiotics, probiotics, or alcohol. SIBO testing and treatment should be individualised.
Poor Stomach Acid, Enzyme or Bile Function
Bloating can happen when food is not being broken down properly before it reaches the lower gut. Low stomach acid, insufficient pancreatic enzymes, poor bile flow, or gallbladder issues can leave proteins, fats, and carbohydrates incompletely digested. Those food residues then become fuel for fermentation and irritation. Signs include burping, reflux, nausea, or discomfort after fatty meals.
Gut Dysbiosis
Dysbiosis means the gut microbiome is out of balance. This may include low beneficial bacteria, overgrowth of opportunistic organisms, reduced microbial diversity, or insufficient production of short-chain fatty acids such as butyrate. Healthy gut bacteria help digest fibres, produce beneficial compounds, support immune tolerance, and protect the gut lining. When the balance shifts, bloating can become chronic.
Gluten Sensitivity or Coeliac Disease
For some people, bloating is a clue that gluten or wheat is not being tolerated. Coeliac disease is an autoimmune condition triggered by gluten that can cause bloating, gas, chronic diarrhoea, constipation, nausea, and poor nutrient absorption. Importantly, you should not remove gluten before proper coeliac testing because testing is most accurate while you are still eating gluten.
Stress and Nervous System Dysregulation
Your gut is not separate from your brain. Stress changes stomach acid, enzyme output, bile flow, gut motility, blood flow to the digestive tract, immune activity, and pain sensitivity. This is why people often say their stomach bloats when they are stressed, even when their diet has not changed. Shifting from sympathetic fight-or-flight tone toward parasympathetic rest-and-digest tone directly supports digestive function.
Hormonal Changes
Many women notice bloating before their period, around ovulation, during perimenopause, or with changes in hormonal contraception. Progesterone can slow intestinal transit, worsening constipation and bloating in the luteal phase. Oestrogen shifts may also affect fluid retention and microbiome patterns. Hormonal bloating often appears cyclically alongside breast tenderness, mood changes, or worsening constipation.
Inflammation or Gut Barrier Dysfunction
When the gut barrier is irritated or inflamed, larger food particles, microbial products, and inflammatory signals may interact more strongly with the immune system. In functional medicine we ask what is irritating the barrier: infections, dysbiosis, medications, alcohol, food reactions, stress chemistry, poor sleep, nutrient depletion, or inflammatory bowel conditions. The barrier is a system, not a single diagnosis.
When Bloating Needs Medical Evaluation
Most bloating is not dangerous, but persistent or severe bloating should be assessed, especially if red flags are present.
Seek medical assessment promptly if bloating is accompanied by:
Most bloating is not dangerous. But these symptoms alongside persistent bloating warrant prompt clinical evaluation rather than a wait-and-see approach.
Bloating can overlap with IBS, coeliac disease, inflammatory bowel disease, ovarian or pelvic conditions, infection, and medication effects. If in doubt, get assessed.
What Functional Medicine Testing May Consider
A personalised workup depends on your symptoms and history. The goal is not to test everything. The goal is to test intelligently based on the pattern.
| Area to Assess | What We Are Looking For |
|---|---|
| Comprehensive stool testing | Microbiome balance, pathogens, inflammation markers, pancreatic elastase, fat digestion, and intestinal immune markers including secretory IgA and zonulin |
| SIBO breath testing | Hydrogen, methane, and hydrogen sulphide gas patterns indicating bacterial overgrowth in the small intestine — indicated when symptoms fit the clinical pattern |
| Coeliac screening | Tissue transglutaminase antibodies and total IgA — must be done before gluten removal for accurate results |
| Food sensitivity assessment | IgG-mediated food reactivity and structured elimination-rechallenge planning based on symptom history and clinical presentation |
| Thyroid markers | Full thyroid panel including T3 conversion when constipation, fatigue, cold intolerance, or weight gain are part of the picture |
| Hormone assessment | DUTCH hormone testing when bloating is cyclical or tracks with the menstrual cycle, perimenopause, or hormonal contraception changes |
| Nutrient status | Iron, B12, zinc, magnesium, and inflammatory markers that may be depleted in the context of chronic gut dysfunction and malabsorption |
| Medication and lifestyle review | Review of medications, supplements, alcohol intake, diet patterns, stress load, and sleep quality as contributors to the gut environment |
What You Can Try Before Your Appointment
Start with the basics for two weeks. Eat slowly and chew thoroughly. Avoid large meals late at night. Reduce carbonated drinks, chewing gum, and eating while rushed. Aim for daily bowel movements. Hydrate consistently. Take a 10-minute walk after meals.
Track when bloating occurs: immediately after eating, several hours later, before your period, after dairy, after wheat, after high-fibre foods, or during stress.
Avoid jumping into extreme restriction. A long-term low-FODMAP, gluten-free, dairy-free, probiotic-heavy, or supplement-heavy plan can sometimes make gut resilience worse if it is not targeted.
The Functional Medicine Approach to Bloating
A root-cause approach often follows a version of the 4R framework:
Remove triggers such as pathogens, food irritants, alcohol excess, or inflammatory exposures.
Replace missing digestive support when indicated, such as stomach acid, enzymes, or bile support.
Reinoculate with targeted probiotics, prebiotics, or food strategies to rebuild microbial balance.
Repair the gut lining, immune tolerance, and lifestyle foundations such as sleep, stress regulation, and nutrient sufficiency.
Frequently Asked Questions
Healthy foods can still cause bloating if you have constipation, SIBO, dysbiosis, low digestive capacity, stress-related motility changes, or food intolerance. The problem may not be the food itself, but how your gut is processing it.
Many people find that removing foods temporarily provides partial relief, but symptoms return because the underlying gut environment has not been addressed. This is where functional testing is valuable.
Common triggers include dairy, wheat, onions, garlic, beans, lentils, apples, pears, carbonated drinks, sugar alcohols, alcohol, and very large high-fibre meals. Triggers vary widely from person to person.
Importantly, many of these foods are nutritious and the goal is not permanent avoidance. The goal is to understand why your gut is reacting and address the underlying driver so that tolerance improves over time.
Yes. Cyclical bloating before your period, around ovulation, or during perimenopause may reflect hormone-related changes in motility, fluid retention, and gut sensitivity. Progesterone slows gut transit in the luteal phase, which can worsen both constipation and bloating significantly.
If your bloating tracks with your cycle, hormonal assessment alongside gut investigation is usually warranted.
Not always. SIBO is one possible cause, especially when bloating occurs soon after carbohydrates or worsens with fibre and probiotics. But constipation, food intolerances, stress, coeliac disease, poor digestion, and dysbiosis can look very similar.
Treating suspected SIBO without testing and without understanding the terrain that allowed it to develop can lead to relapse. A proper workup before treatment is always worth doing.
The lasting solution depends on the cause. Start by improving bowel regularity, meal hygiene, hydration, and stress physiology. Eat slowly, chew thoroughly, walk after meals, and track when bloating is worst.
If bloating persists despite these changes, functional testing can help identify whether the driver is microbial, digestive, immune, hormonal, or motility-related. Guessing with supplements or restriction plans without knowing the cause often makes things worse over time.
If your stomach is always bloated, your body is giving you information. The answer is not to ignore it, restrict more foods, or keep guessing with random supplements.
Your body is giving you information. It is time to listen to it.
At Wave Functional Health we help identify the underlying drivers of chronic bloating and build a personalised plan based on your symptoms, history, and testing. The answer is not to restrict more foods or keep guessing with random supplements. It is to actually look in the right places.
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