What should you know about different types of lactose intolerance?

Primary lactose intolerance develops when the intestine makes less lactase over time. Secondary lactose intolerance follows irritation or injury to the small intestine, and may improve when the underlying problem is treated. Congenital or developmental forms are uncommon and begin very early in life. Undigested lactose can draw water into the bowel and be fermented by gut bacteria, causing bloating, abdominal pain and diarrhoea. Lactose intolerance is different from a milk allergy, which involves the immune system.

Keep a food and symptom diary, noting the portion and timing rather than removing every dairy food immediately. Many people tolerate small amounts, especially with a meal, while yoghurt or hard cheese may be easier than some milk products. A clinician can consider Food Intolerance Testing and check for another explanation. Nutrition Counselling can help protect calcium and vitamin intake if dairy needs to be limited.

Arrange medical review for ongoing diarrhoea, weight loss, blood in the stool, night symptoms, repeated vomiting or symptoms that do not follow dairy intake. Get urgent help for breathing difficulty, facial swelling, widespread hives or collapse after milk, because those features can signal a severe allergic reaction rather than lactose intolerance. Babies with poor feeding or dehydration need prompt assessment.

Could this be lactose intolerance or milk allergy? Should I try a supervised reduction and reintroduction? Do I need testing? How can I meet my calcium needs? Could a bowel condition be causing secondary intolerance?