What are the first signs of lactose intolerance?

Lactose is the natural sugar in milk. Lactose intolerance happens when the small intestine does not provide enough lactase, the enzyme that breaks lactose down. Unabsorbed lactose reaches the large intestine, where bacteria ferment it and produce gas and extra fluid. Symptoms may begin after milk, ice cream, soft cheese or other dairy, and their intensity can depend on the amount eaten. Abdominal pain, bloating and diarrhoea can also have many other causes, so a symptom pattern is not a diagnosis.

Keep a brief food-and-symptom diary: record the dairy product, portion, timing and symptoms. Do not remove every source of dairy for a long period without a nutritional plan, because calcium and vitamin D still matter. A clinician may suggest a structured dietary trial or Food Intolerance Testing when appropriate. Nutrition Counselling can help you choose suitable alternatives and check that your diet remains balanced.

Arrange a medical assessment if symptoms are persistent, worsening, disturb sleep, cause weight loss, or include blood in the stool, repeated vomiting, dehydration or severe abdominal pain. Seek urgent help for swelling of the lips or throat, wheezing or trouble breathing after dairy, because those features suggest an allergic reaction rather than lactose intolerance.

Could another digestive condition explain this pattern? Should I try a supervised lactose reduction? How can I meet calcium needs if dairy is limited? Would testing add useful information?