What should you know about lactose intolerance?

Lactose is the natural sugar in milk and many dairy foods. The enzyme lactase normally breaks it down before it reaches the colon. When lactase is low, undigested lactose is fermented by gut bacteria, drawing in fluid and producing gas. A person may notice abdominal pain, bloating, wind, rumbling or diarrhoea after milk, ice cream or soft cheese. Symptoms depend on the amount eaten and can vary from one food to another. Lactose intolerance is different from a milk allergy, which involves the immune system and may cause hives, swelling or breathing problems.

Keep a brief food-and-symptom diary to identify patterns, then discuss a measured reduction of lactose with a clinician or dietitian. Some people tolerate yoghurt, hard cheese or lactose-free milk better because lactose amounts and digestion differ. Read labels for milk, whey and milk solids, and choose calcium- and vitamin-rich alternatives when reducing dairy. Avoid cutting out many foods for a long time without advice, because a tailored plan protects nutritional balance. A clinician may consider Food Intolerance Testing and Nutrition Counselling when symptoms are persistent or the diagnosis is uncertain.

Arrange a medical review if diarrhoea, pain or bloating keeps returning, wakes you, limits eating, or causes unplanned weight loss. Seek urgent help for severe or worsening abdominal pain, repeated vomiting, fainting, blood in the stool, facial swelling or trouble breathing. Recurring symptoms can have causes other than lactose intolerance, including coeliac disease, infection or inflammatory bowel conditions.

Could another condition explain my symptoms? Which foods should I test first, and how can I maintain calcium intake? Would a supervised lactose reduction or Food Intolerance Testing help? When should I return if symptoms continue?