Lactose intolerance and the digestive system

Lactase is an enzyme made in the lining of the small intestine. It normally splits lactose into smaller sugars that can be absorbed. If lactase is limited, undigested lactose moves into the colon. Bacteria ferment it and draw water into the bowel, producing gas, abdominal cramping, bloating and diarrhoea. This process is different from a milk allergy, which involves the immune system and can cause symptoms outside digestion.

Notice whether symptoms follow milk, ice cream, creamy sauces or other lactose-containing foods, and record the portion and timing. Many people can tolerate some lactose, especially when it is spread across meals. Lactose-free products can provide a practical alternative. If you remove dairy, replace its nutrients deliberately and consider Nutrition Counselling. A clinician may discuss Food Intolerance Testing when the history does not give a clear answer.

Seek care for ongoing diarrhoea, significant dehydration, blood in stool, unexplained weight loss, nighttime symptoms or persistent Abdominal Pain. Fever or chills do not fit the usual digestive mechanism of lactose intolerance and should prompt medical review, particularly if symptoms are intense or new.

Ask how your symptoms map to Lactose Intolerance, whether another bowel problem is possible, and how to test a food trigger safely. Ask which calcium-containing foods suit you if dairy is reduced.