Breastfeeding and lactose intolerance: what to know

Lactose is the natural sugar in milk. Lactose intolerance happens when the digestive system does not break down enough lactose, which can lead to abdominal pain, bloating, gas or diarrhoea after lactose is consumed. A baby’s unsettled behaviour or changes in stools do not by themselves prove lactose intolerance. Breast milk remains suitable for most babies, and removing dairy from the parent’s diet does not remove lactose from breast milk.

Cow’s-milk protein allergy is different and may involve blood or mucus in stools, eczema, vomiting or breathing symptoms. These concerns need clinical advice rather than a self-directed restrictive diet.

Keep a brief record of feeds, foods, stool changes, vomiting, crying and abdominal discomfort. Note whether symptoms occur repeatedly after a particular food and whether the baby is feeding and growing as expected. Continue breastfeeding unless a clinician advises otherwise. Do not give a baby lactase products or change formula without professional guidance.

A doctor, paediatrician or dietitian can decide whether testing or a supervised dietary trial is appropriate. [Food Intolerance Testing](/treatments/diagnostics-and-screening/food-intolerance-testing/) and [Nutrition Counselling](/treatments/lifestyle-and-wellness/nutrition-counselling/) may help when symptoms persist.

Arrange prompt medical advice for repeated vomiting, poor feeding, fewer wet nappies, blood in the stool, breathing difficulty, facial swelling, marked sleepiness or poor weight gain. Seek urgent help for breathing trouble, collapse or a rapidly worsening allergic reaction. For ongoing loose stools or discomfort, discuss the pattern with a clinician and read about [Diarrhoea](/symptoms/diarrhoea/), [Bloating](/symptoms/bloating/) or [Abdominal Pain](/symptoms/abdominal-pain/).

Could these symptoms fit lactose intolerance, allergy, infection or another feeding problem? Should I change my diet, and how would we protect my nutrition? Does my baby need an examination, a growth review or supervised testing?