What should you know about celiac and lactose intolerance?

Celiac disease is an immune reaction to gluten that can injure the small-bowel lining. Lactose intolerance happens when the body does not digest lactose, the natural sugar in milk, effectively; undigested lactose is fermented in the bowel and may produce gas, cramps and loose stools. Lactose intolerance does not mean that a person has celiac disease.

Celiac disease can sometimes lead to temporary lactose intolerance when the bowel lining is irritated, so symptoms may change after treatment. Similar symptoms can also arise from other digestive conditions. Avoiding several food groups without advice can reduce calcium, fibre or other nutrients and may make the cause harder to identify.

Keep a food and symptom diary that records dairy portions, other ingredients, timing and bowel changes. Arrange medical assessment before adopting a strict gluten-free diet if celiac disease is possible, because testing may be affected by dietary changes. A clinician or dietitian can discuss food intolerance testing, a structured lactose reduction and suitable calcium sources. Do not rely on unvalidated home tests to diagnose either condition.

Seek prompt medical care for blood in stools, persistent vomiting, severe abdominal pain, dehydration, unintentional weight loss, fever or symptoms that wake you repeatedly at night. Get emergency help for fainting, a swollen painful abdomen, breathing difficulty or facial swelling after food.

Ask whether your pattern fits lactose intolerance, whether celiac testing is needed before changing gluten intake, and how to maintain calcium and other nutrients during any elimination trial.