Infant lactose intolerance: what parents should know

Lactose is the natural sugar in milk. When the gut does not break it down well, undigested lactose can draw water into the bowel and be fermented, leading to wind, loose stools, bloating, or abdominal discomfort. Lactose Intolerance is different from a milk-protein allergy, which can involve skin or breathing symptoms and needs a different plan.

In a young infant, crying, frequent stools, spit-up, and changing nappies are common for many reasons. A pattern after feeds is useful, but it does not prove lactose intolerance. A clinician may review growth, hydration, stool features, feeding history, and any recent illness.

Keep a short record of feeds, stool changes, vomiting, discomfort, and wet nappies. Continue the feeding plan advised for your baby unless a clinician tells you to change it. Do not dilute formula, switch formula repeatedly, or remove milk without professional guidance, because infants need dependable nutrition. Nutrition Counselling can help protect energy and calcium intake when a restricted plan is genuinely needed. Food Intolerance Testing may be discussed when the history remains unclear.

Seek urgent medical care for blood in the stool, repeated vomiting, a swollen or hard abdomen, breathing difficulty, facial swelling, marked sleepiness, or signs of dehydration such as very few wet nappies. Arrange a prompt review if symptoms persist, feeding is difficult, weight gain is a concern, or diarrhoea follows most feeds. A very young infant who seems unwell should be assessed without delay.

Do the symptoms fit lactose intolerance or another feeding problem? Is my baby growing and hydrated as expected? Should we change the milk, and how will nutrition be protected? What stool or vomiting changes should prompt urgent help?