What should you know about partial lactose intolerance?

Lactose is the natural sugar in milk. The small intestine makes lactase to digest it; when lactase activity is limited, undigested lactose reaches the bowel and is fermented. This can cause bloating, abdominal pain, gas or diarrhoea. Symptoms depend on portion size, the rest of the meal and individual tolerance.

Lactose intolerance is different from a milk allergy, which can involve hives, swelling, wheezing or vomiting soon after exposure. A symptom diary can show whether dairy, another food or a bowel condition better explains the pattern.

Track the food, portion, timing and symptoms rather than removing every dairy product immediately. Many people can test a smaller portion with a meal, choose lactose-free alternatives or use yoghurt and hard cheese if tolerated. Read labels for milk, lactose, whey and milk powder.

Protect calcium and vitamin D intake when reducing dairy. Nutrition Counselling can help plan suitable alternatives. A clinician may discuss Food Intolerance Testing or a supervised dietary trial, especially when symptoms are frequent, severe or unclear.

Arrange medical advice for ongoing diarrhoea, weight loss, blood in stool, night-time symptoms, fever, persistent abdominal pain or signs of poor nutrition. Seek urgent help for facial or throat swelling, breathing difficulty, faintness or a rapidly spreading itchy rash after milk; these features suggest a possible allergy rather than lactose intolerance.

Ask: Does my pattern fit Lactose Intolerance? Could another bowel condition explain the symptoms? Which foods can I trial safely, and how will I replace calcium and vitamin D? Would testing or a dietitian review be useful?