Lactose intolerance is when you get stomach pain because you are unable to fully digest the sugar (lactose) in milk and dairy products. It occurs when your small intestine does not produce enough lactase, an enzyme responsible for breaking down lactose into simpler sugars that can be easily absorbed into the bloodstream.
Lactose intolerance is different from a milk allergy, which is an immune system response to the proteins found in milk and dairy products.
Too little of an enzyme (lactase) produced in your small intestine is usually responsible for lactose intolerance. When lactose is not adequately broken down, it remains in your intestine, where it can ferment and cause various uncomfortable symptoms.
Symptoms of lactose intolerance usually develop within 30 minutes to 2 hours after consuming dairy products. They include:
- Abdominal pain
- Stomach cramps