What should you know about genetic lactose intolerance?

Lactase is the enzyme that breaks down lactose, the natural sugar in milk. Some people gradually make less lactase after childhood because of inherited biology. Undigested lactose can draw water into the bowel and be fermented by gut bacteria, causing bloating, abdominal pain, wind or diarrhoea after dairy. The amount that triggers symptoms varies, and yoghurt or hard cheese may be easier to tolerate than milk for some people. This is different from a food allergy, which involves the immune system.

Keep a short food-and-symptom record, including the type and portion of dairy and when symptoms begin. A clinician may discuss a supervised dietary trial or Food Intolerance Testing; a genetic result alone does not show how much lactose you can tolerate. Avoid removing every dairy food without a replacement plan. Nutrition Counselling can help you maintain calcium, vitamin D and protein through suitable foods or fortified alternatives. Use lactose-free products or lactase products only after discussing whether they fit your situation.

Arrange medical review if symptoms are persistent, worsening, occur without dairy, or lead to weight loss, dehydration or difficulty eating. Seek urgent care for severe abdominal pain, repeated vomiting, faintness, blood in stool, facial swelling, wheezing or trouble breathing. Those allergy-type symptoms are not explained by lactose intolerance.

Could another digestive condition explain my symptoms? Would a supervised lactose reduction or testing be useful? Which dairy foods and fortified alternatives can meet my nutritional needs? How should I reintroduce lactose safely?