Lactose intolerance and malabsorption

Lactase is an enzyme on the surface of the small intestine. If there is not enough of it, lactose passes onward without being absorbed. Gut bacteria then ferment the lactose, producing gas and drawing water into the bowel. The resulting pattern may include bloating, cramps, loose stools and diarrhoea after milk or other lactose-containing foods. Primary lactase reduction can develop with age; temporary malabsorption can also follow irritation or illness affecting the small intestine.

Keep a food and symptom diary, including the type and portion of dairy and how soon symptoms appear. A clinician may suggest a structured dietary trial or Food Intolerance Testing when appropriate. Do not use a restrictive diet as a substitute for assessment if symptoms persist. Lactose-free milk, suitable alternatives and careful portion planning may help. Nutrition Counselling can support calcium and vitamin D intake while you identify your tolerance.

Book an appointment for ongoing diarrhoea, unintended weight loss, symptoms that occur without dairy, nighttime symptoms, blood in stool, fever or repeated vomiting. Seek urgent care for severe pain, marked weakness, signs of dehydration, facial swelling or breathing difficulty. These findings require a broader assessment and may not be explained by lactose malabsorption alone.

Ask whether your symptoms suggest lactose malabsorption, whether coeliac disease or another bowel problem should be checked, and how to test tolerance without losing important nutrients.