What should you know about secondary lactose intolerance treatment?

The small intestine makes lactase, an enzyme that digests lactose in milk and some dairy foods. A bowel illness or condition can temporarily affect the intestinal lining and reduce lactase activity. Lactose then passes into the colon, where bacteria break it down and may produce bloating, abdominal pain, wind or diarrhoea. This pattern is different from assuming every dairy symptom is lactose intolerance; infection, coeliac disease, inflammatory bowel disease and other causes can overlap. The underlying problem determines recovery and treatment.

A clinician may recommend reducing lactose for a limited period while the suspected bowel problem is assessed or treated. Keep a food and symptom record, and avoid removing all dairy for a long time without a nutrition plan because calcium and other nutrients still matter. Lactose-free alternatives or lactase products may help some people, but check their suitability with a pharmacist or clinician. Reintroduce small amounts gradually only when advised or when symptoms are settling. Nutrition Counselling and Food Intolerance Testing may be useful, while Lactose Intolerance, Abdominal Pain, Bloating and Diarrhoea provide related information.

Seek medical advice for ongoing diarrhoea, weight loss, blood in stool, fever, repeated vomiting, dehydration, severe abdominal pain or symptoms that began after a significant bowel illness. Get urgent help for severe pain with a swollen abdomen, fainting, confusion or inability to keep fluids down. These warning signs need assessment rather than being attributed to lactose alone.

What underlying condition could be affecting lactose digestion? How long should I reduce lactose? How can I protect my nutrition, and when should I try reintroduction? Is testing appropriate?