What should you know about OTC for lactose intolerance?

Lactose is the sugar in milk. When the small intestine makes too little lactase, undigested lactose reaches the large bowel, where bacteria break it down and produce gas. This can lead to [Bloating](/symptoms/bloating/), cramps, and [Diarrhoea](/symptoms/diarrhoea/) after dairy.

The amount tolerated varies. Lactose-free products, yoghurt, or harder cheeses may be easier for some people than a large serving of milk. Symptoms can also come from other food or bowel conditions, so a pattern alone does not confirm the diagnosis.

A lactase tablet or liquid can be taken as directed with a dairy-containing meal; it works only on lactose in that meal. Follow the product label and keep a food-and-symptom record. Reduce lactose gradually rather than removing all dairy without planning calcium and vitamin sources.

A pharmacist or dietitian can help compare lactose-free foods and supplements. [Nutrition Counselling](/treatments/lifestyle-and-wellness/nutrition-counselling/) is useful when symptoms have led to a very restricted diet.

Arrange an appointment for weight loss, blood in stool, persistent vomiting, fever, night-time diarrhoea, symptoms unrelated to dairy, or ongoing [Abdominal Pain](/symptoms/abdominal-pain/). Seek urgent help for severe pain, dehydration, or swelling of the lips or throat after food.

Ask whether your symptoms fit lactose intolerance, whether another condition should be considered, and how to maintain balanced nutrition. Ask if [Food Intolerance Testing](/treatments/diagnostics-and-screening/food-intolerance-testing/) is appropriate and how to interpret the result.