Stomach Bloating: Causes and How to Get Relief

What bloating feels like

People describe bloating as feeling "puffed up", tight, full, or like a balloon in the belly. It can come with:

• a visibly larger belly, often worse by evening and flatter in the morning
• belching or passing gas
• rumbling and gurgling
• cramping or discomfort
• clothes feeling tight

Bloating (the feeling) and distension (a measurable increase in belly size) often go together but not always. Many people with bloating, especially those with IBS, do not have more gas than others. Their gut is more sensitive to normal amounts of gas, or the belly wall muscles relax and push out in response to gas.

Common causes of stomach bloating

Less common and serious causes

• Celiac disease: an immune reaction to gluten with bloating, diarrhea, weight loss, anemia and fatigue.
• Small intestinal bacterial overgrowth (SIBO): too many bacteria in the small intestine ferment food, causing bloating soon after eating. More common after bowel surgery and with diabetes.
• Gastroparesis: slow stomach emptying with fullness, nausea and vomiting, often in diabetes.
• Ovarian cancer: persistent bloating, feeling full quickly, pelvic or belly pain, and needing to urinate often. It is easily mistaken for IBS, especially in women over 50 who have new IBS-like symptoms.
• Ascites: fluid in the belly from liver cirrhosis, heart failure or cancer, causing steady swelling, weight gain and breathlessness.
• Bowel obstruction: a blockage causing a swollen belly, cramping pain, vomiting and no passing of gas.
• Pancreatic insufficiency: pale, greasy, floating stools with bloating and weight loss.
• Medicines: opioids, some diabetes medicines (metformin, GLP-1 agonists, acarbose), fiber supplements started too quickly, and antibiotics.

Bloating and weight gain

Bloating varies through the day and is usually worst in the evening. A belly that keeps getting bigger over weeks, without going down overnight, is different: it can mean fat gain, fluid (ascites), a large ovarian cyst or fibroids, or a pregnancy. It should be checked by a doctor.

When to worry about bloating

The features that need prompt assessment are listed in the triage box above. The key questions are: is it persistent, is it getting worse, and are there other symptoms such as weight loss, bleeding, vomiting or a change in bowel habit? New, persistent bloating in women over 50 deserves a CA-125 blood test and pelvic ultrasound.

How doctors find the cause

Your doctor will ask when bloating happens, its relation to meals and bowel movements, diet, medicines, periods and any red flags, and will examine your abdomen. Tests depend on the clues:

• blood tests: blood count, celiac antibodies, and CA-125 in women over 50 with persistent symptoms
• stool tests for infection or inflammation
• breath tests for lactose intolerance or SIBO
• pelvic or abdominal ultrasound
• endoscopy or colonoscopy for red flags or age-appropriate screening

Bloating relief and prevention

Quick relief

• Walk for 10 to 15 minutes after meals to help gas move through.
• Apply gentle heat to the belly.
• Massage the belly in a clockwise circular direction.
• Try simethicone or activated charcoal from a pharmacy, following the label. Evidence is modest.
• Peppermint oil capsules (enteric-coated) can ease IBS bloating and cramping. They may worsen reflux.

Prevention

• Eat slowly, chew well and avoid talking while chewing.
• Cut down on fizzy drinks, chewing gum and sugar-free sweeteners.
• Eat smaller, more frequent meals and less fatty food.
• Treat constipation with fluids, gradual fiber increases and regular exercise.
• Keep a food diary to spot triggers.
• If IBS is diagnosed, a low-FODMAP diet, ideally guided by a dietitian, helps many people. It restricts fermentable carbohydrates for 2 to 6 weeks, then reintroduces them to find personal triggers.
• Try lactose-free dairy or lactase tablets if dairy is a trigger.

Some probiotics help some people with IBS-related bloating, but results vary. Try one for 4 weeks and stop if there is no benefit.

Frequently asked questions

What causes stomach bloating?

Most bloating is caused by gas from food, swallowed air, constipation, irritable bowel syndrome, overeating or food intolerances such as lactose. Hormonal changes before a period also cause bloating. Less commonly, celiac disease, SIBO, gastroparesis, fluid in the belly or ovarian cancer are responsible.

Why am I bloated all the time?

Constant bloating is often due to IBS, constipation, food intolerances or SIBO. Persistent bloating that is new, getting worse, or comes with weight loss, bleeding or loss of appetite should be checked, especially in women over 50, to rule out ovarian cancer and other conditions.

How do I get rid of bloating fast?

Go for a short walk, apply gentle heat, and massage your belly clockwise. Avoid fizzy drinks and gum. Simethicone or peppermint oil capsules may help. If constipation is the cause, fluids and fiber help over a day or two.

Is bloating a sign of ovarian cancer?

It can be. Ovarian cancer often causes persistent bloating, early fullness, pelvic pain and urinary frequency. These symptoms are common and usually have harmless causes, but if they occur most days for 3 weeks or more, especially after age 50, see a doctor.

What foods cause bloating?

Common culprits are beans, lentils, cabbage, broccoli, onions, garlic, wheat, dairy (in lactose intolerance), apples, pears, fizzy drinks and sugar-free sweeteners such as sorbitol. Triggers vary from person to person, so a food diary helps.