Lactose Intolerance

Last Updated: July 3, 2026

Key Points

Symptoms occur after consuming lactose, a sugar in dairy
Caused by the body not making enough lactase enzyme
Symptoms include tummy pain, bloating, and gas
Managed by reducing or avoiding lactose in the diet

Overview

Lactose intolerance means your body has difficulty digesting lactose, a sugar present in milk and other dairy products. This happens because your small intestine doesn't produce enough of an enzyme called lactase, which is needed to break down lactose. When undigested lactose reaches the large intestine, it can cause various uncomfortable digestive symptoms. These symptoms typically appear within minutes to a few hours after consuming foods or drinks containing lactose. Managing lactose intolerance often involves adjusting your diet to reduce or completely avoid lactose-containing foods. Some people also find relief by taking lactase enzyme supplements before eating dairy.

Signs and Symptoms

Tummy pain or discomfort
Bloating
Increased gas (farting)
Tummy rumbling
Diarrhoea or constipation
Feeling sick or being sick
Headaches
Tiredness
Joint or muscle pain

Things That Increase the Risk

Insufficient production of lactase enzyme
Inflammatory bowel disease
Coeliac disease
Bowel infections
Bowel surgery or injury
Premature birth (often temporary)

Diagnosis

Lactose elimination diet to observe symptom changes
Blood tests
Hydrogen breath test to measure lactose digestion
Gastroscopy for severe, persistent symptoms

Treatment & Management

Reducing or avoiding lactose-containing foods
Taking lactase enzyme supplements before consuming dairy
Treating any underlying health conditions
Choosing lactose-free dairy alternatives

Prevention

Carefully checking food labels for lactose
Limiting portion sizes of dairy products
Using lactase supplements when consuming dairy
Choosing lactose-free or dairy-free food options

Available Treatments

Explore our range of treatment options for Lactose Intolerance: