Bloating

Bloating is a feeling of fullness, pressure, or swelling in your belly. Your abdomen may look larger than usual, but this does not always happen.

A visibly enlarged belly is called abdominal distension. Bloating and distension often occur together, although you can feel bloated without a noticeable change in size.

Bloating is commonly linked to digestion, food, swallowed air, or constipation. It can also occur with conditions affecting the intestines or other organs. Its timing and related symptoms can help identify the cause.

Your belly may feel tight, stretched, heavy, or uncomfortably full. You might notice pressure in the upper or lower abdomen, increased burping or gas, or rumbling sounds.

Clothes may feel tighter around your waist. Swelling may increase during the day or after meals and improve after passing stool or gas.

Related symptoms can include constipation, diarrhoea, heartburn, nausea, cramps, or feeling full after eating a small amount. Bloating around a menstrual period may occur with pelvic discomfort or temporary fluid retention.

Swallowed air and digestive gas are common causes. Eating quickly, chewing gum, smoking, using a straw, and drinking fizzy beverages can increase swallowed air. Gut bacteria also produce gas while breaking down food.

Certain foods can produce gas or draw water into the bowel. Examples include beans, lentils, onions, some fruits, and products containing certain sweeteners. Dairy foods may cause symptoms if you do not digest lactose well.

Constipation can slow the movement of stool and gas. Bloating may improve after a bowel movement.

Irritable bowel syndrome, or IBS, can cause bloating with abdominal pain and changes in bowel habits. The bowel may be unusually sensitive even when gas levels are normal.

Less common causes include coeliac disease, small intestinal bacterial overgrowth, and medicines that cause constipation or alter digestion.

Persistent bloating can occasionally relate to abdominal fluid or a condition affecting the ovaries, liver, pancreas, stomach, or bowel. Bloating alone cannot identify these causes.

Seek emergency help if bloating occurs with sudden or severe abdominal pain, fainting, difficulty breathing, vomiting blood, or a hard and very tender belly.

Get urgent, same-day medical advice if your belly is becoming increasingly swollen and painful, especially if you are vomiting or cannot pass stool or gas. These symptoms can occur when the bowel is blocked. Also seek prompt advice for fever, blood in your stool, or black, tar-like stool.

Book a routine appointment if bloating:

• Happens regularly or is getting worse
• Continues despite simple diet and bowel-habit changes
• Comes with unexplained weight loss or reduced appetite
• Occurs with ongoing diarrhoea, constipation, or abdominal pain
• Causes frequent early fullness or difficulty eating
• Is new and persistent, particularly after menopause

These features do not necessarily indicate a serious cause, but they should be assessed rather than managed through repeated food restriction.

A healthcare professional will ask when the bloating started, whether it relates to meals or bowel movements, and which other symptoms occur. They may ask about your diet, menstrual cycle, medicines, previous surgery, family history, and weight changes.

An examination may check for tenderness, swelling, a mass, or unusual bowel sounds. Many people do not need extensive testing.

Depending on your symptoms, tests may include blood tests for anaemia, inflammation, or coeliac disease. Breath tests can sometimes assess lactose digestion or bacterial overgrowth. Stool tests, ultrasound, other scans, or a camera examination of the digestive tract may be considered if symptoms, examination findings, or risk factors warrant them.

Treatment depends on the cause. Eat slowly, avoid gulping drinks, and consider smaller, regular meals instead of large ones. Reducing fizzy drinks, chewing gum, and habits that increase swallowed air may help.

If you are constipated, gradually increasing suitable fibre, drinking enough fluid, and staying active may improve regularity. Increasing fibre too quickly can temporarily worsen gas.

Keep a short record of meals, bowel movements, and symptoms to identify repeatable triggers. Do not remove several food groups without professional advice, as restrictive diets can cause nutritional gaps.

If IBS is suspected, a clinician or dietitian may recommend a structured approach such as a low-FODMAP diet. FODMAPs are carbohydrates that some people absorb poorly. This diet should be temporary and followed by careful food reintroduction.

Medicines may help when constipation, IBS, or another condition is identified. Ask a pharmacist or clinician which option suits your symptoms rather than repeatedly trying different remedies. Evidence for probiotics and many marketed “detox” products is inconsistent.

Meal-related bloating often settles within several hours. Bloating caused by constipation may improve when bowel habits return to normal. Symptoms linked to IBS or food intolerance may come and go over longer periods.

A symptom diary and targeted changes are often more useful than trying many treatments at once. Arrange follow-up if symptoms persist, become more frequent, or change in character.

Is bloating always caused by excess gas?

No. The bowel may be sensitive to normal amounts of gas, or the abdominal muscles and diaphragm may respond differently during digestion. Constipation, fluid, and other conditions can also cause swelling.

Why is bloating worse later in the day?

Food, fluid, gas, and stool accumulate during the day. Eating quickly, having large meals, and slower bowel movement can contribute.

Can periods cause bloating?

Yes. Hormone changes can affect fluid balance and bowel movement. Bloating that is new, persistent, or unrelated to the menstrual cycle should be reviewed.

Can stress make bloating worse?

Yes. The brain and digestive tract communicate closely, and stress can affect bowel movement, muscle tension, and sensitivity to pressure. This does not mean the symptom is imaginary.

Could persistent bloating be cancer?

Most bloating is not caused by cancer. However, new and persistent bloating, especially with weight loss, reduced appetite, early fullness, pelvic pain, or changes in bowel habits, should be assessed.