Upset stomach, bloating and gas: what to know

Bloating is a feeling of fullness or pressure, sometimes with visible abdominal swelling. Gas may come from air swallowed while eating or from bacteria breaking down food in the bowel. Indigestion, constipation, a food intolerance, or irritable bowel syndrome can produce several of these symptoms together. Coeliac disease, giardiasis, and Helicobacter pylori infection are less common possibilities that need clinical assessment rather than self-diagnosis.

Notice the pattern: symptoms after milk, soft cheese, or ice cream can fit lactose intolerance; symptoms after a wider range of foods may suggest food intolerance. Ongoing diarrhoea, weight loss, blood in stool, repeated vomiting, or symptoms that wake you should be assessed.

Eat slowly, choose smaller meals, and reduce fizzy drinks, chewing gum, and foods that clearly trigger symptoms. Gentle walking may help gas move through the bowel. Drink fluids regularly and address constipation with gradual fibre changes unless a clinician has advised otherwise. Keep a short food-and-symptom diary so a GP or nutrition counsellor can see timing, stool changes, and possible triggers. Avoid cutting out major food groups for a long period without advice.

Arrange a GP appointment if symptoms keep returning, persist despite simple changes, or interfere with eating, sleep, or daily activities. Seek urgent medical help for severe or rapidly worsening abdominal pain, a hard swollen abdomen with repeated vomiting, black or bloody stool, fainting, trouble breathing, or inability to pass stool or gas. A clinician may examine your abdomen and decide whether tests are needed.

Ask whether your pattern fits constipation, food intolerance, irritable bowel syndrome, or another condition; which foods are reasonable to trial; whether testing for coeliac disease or infection is appropriate; and which warning signs should prompt earlier review.