Lactose Intolerance

For people who have lactose intolerance, dairy products like milk, cheese, and ice cream can cause painful and sometimes embarrassing symptoms like belly pain, cramps, gas, and diarrhea.

Lactose is a sugar found in milk and other dairy products. The gut can’t absorb lactose, so your body produces a special protein to help. This protein is called lactase. Lactase breaks lactose down into two simple sugars called glucose and galactose. Glucose and galactose can then be absorbed by your gut.

Lactose intolerance is what happens when your gut doesn’t make enough lactase. If you don’t have enough lactase to break down the lactose from dairy, the bacteria in your gut break down the lactose instead. This is what causes your symptoms.

Lactose intolerance is rare in children under two years old. Most people with lactose intolerance have symptoms by the age of sixteen. Your body makes less lactase as you age. Lactose intolerance tends to run in families.


Some of the symptoms you might get with lactose intolerance include:

  • Belly pain
  • Cramps
  • Bloating
  • Gas
  • Diarrhea, and
  • Nausea

You will typically start to feel these symptoms between half an hour and two hours after you eat or drink dairy products.

These symptoms are common and can be caused by a number of other conditions.


If you’re having symptoms, your healthcare provider may ask you to avoid milk and other dairy products for two weeks. After those 2 weeks, you may be told to slowly start eating and drinking dairy products again.

If your symptoms go away when you stop eating dairy products, and then come back when you start eating them again, you may be lactose intolerant.

If your symptoms don’t improve when you stop eating dairy, you might have a different health problem.

Your healthcare provider may want to do some tests to make sure that you’re lactose intolerant. The two main tests are the hydrogen breath test and the stool acidity test.

For the breath test, you’ll drink a solution that contains lactose, and then breathe into a machine every so often. The machine will measure the amount of hydrogen in your breath. If you have lactose intolerance, your breath will contain a lot of hydrogen.

The stool acidity test looks at your fecal waste. This test is usually used to detect lactose intolerance in children. Lactose makes stool acidic.


Lactose intolerance doesn’t have a specific treatment. There’s no way to make your gut produce more lactase.

People with lactose intolerance can usually handle small amounts of dairy. But most people manage their condition by staying away from all foods that contain lactose.

If you want to keep drinking milk and eating dairy products, there are ways to increase your body’s ability to digest them. You might be able to avoid your symptoms by eating or drinking dairy products with other foods You might also find that taking lactase pills before eating or drinking dairy helps your symptoms.

Milk and dairy products are an important source of vitamin D and calcium. If you cut milk and dairy products, talk with your healthcare provider about how to get enough of these nutrients in your diet.

Things to Remember

Lactose intolerance is very common in adults.

Lactose intolerance usually isn’t a serious condition.

Lactose intolerance can usually be managed.

If you’re staying away from dairy, it’s important to find other sources of calcium and vitamin D.

What We Have Learned

  1. Lactose is a sugar found in fruits and vegetables. True or False?
    The answer is false. Lactose is found in milk and other dairy products.

  2. If you have lactose intolerance, you might get belly pain, gas, or diarrhea after you drink milk or eat other dairy products. True or False?
    The answer is true. You may need to avoid dairy products altogether to relieve your symptoms.