What causes stomach bloating and gas?

Eating quickly, chewing gum, fizzy drinks and talking while eating can increase swallowed air. Fermentation of carbohydrates in the bowel naturally produces gas, while constipation can make pressure and distension more noticeable. Irritable Bowel Syndrome may cause bloating with abdominal discomfort and altered bowel habits. Lactose Intolerance or another Food Intolerance can trigger symptoms after particular foods. Coeliac Disease, Helicobacter Pylori Infection or Giardiasis are less common possibilities and usually come with other features such as diarrhoea, weight change, nausea or ongoing upper abdominal discomfort. Bloating is a symptom rather than a diagnosis, and patterns over time are useful.

Eat slowly, reduce fizzy drinks, and notice whether a food, portion size or bowel habit precedes symptoms. Gentle movement and adequate fluids can support bowel regularity. Keep a simple food-and-symptom diary, but avoid removing many food groups without guidance. A clinician or Nutrition Counselling service can help test a suspected intolerance safely and maintain balanced nutrition. Do not start a gluten-free diet before discussing testing for Coeliac Disease, because this can affect the assessment.

Arrange an appointment if bloating is persistent, repeatedly returns, disrupts daily life or comes with unexplained weight loss, blood in stool, ongoing vomiting, persistent diarrhoea, fever, anaemia symptoms or a change in bowel habit. Seek urgent care for severe or rapidly worsening abdominal pain, a swollen rigid abdomen, repeated vomiting or inability to pass stool and gas.

Ask which symptoms suggest constipation, Irritable Bowel Syndrome or Food Intolerance, whether testing is appropriate, and how to change your diet without missing essential nutrients. Bring your food-and-symptom diary.