Skip to content
Font Size

Lactose Intolerance - Exams and Tests

If your doctor thinks you have lactose intolerance, he or she will ask questions about your medical history and do a physical exam. Before making a diagnosis, your doctor may ask that you avoid dairy products for a short time to see if your symptoms improve. You may also be asked to bring in a sample of your stool. The stool of a person who has lactose intolerance is usually loose or watery. It also can be foamy.

To confirm a diagnosis, your doctor may order a:

Recommended Related to Digestive Disorders

Polycystic Liver Disease: Symptoms, Causes, and Treatment

Polycystic liver disease (PLD or PCLD) is a rare condition that causes cysts -- fluid-filled sacs -- to grow throughout the liver. A normal liver has a smooth, uniform appearance. A polycystic liver can look like a cluster of very large grapes. Cysts also can grow independently in different parts of the liver. The cysts, if they get too numerous or large, may cause discomfort and health complications. But most people with polycystic liver disease do not have symptoms and live a normal life. Here...

Read the Polycystic Liver Disease: Symptoms, Causes, and Treatment article > >

  • Hydrogen breath test. This is the most accurate lactose intolerance test. Before the test, you need to avoid certain foods and medicines and cigarettes. On the day of the test, you will drink a liquid that contains lactose and then breathe into a machine several times over a couple of hours. If the hydrogen levels in your breath are high, you may have lactose intolerance. This test is not usually done on babies and very young children, because it can cause severe diarrhea.
  • Lactose tolerance test. This test measures your blood sugar after you eat or drink lactose. After midnight on the night before the test, you should not eat or drink anything. On the day of your test, you will drink a liquid that contains lactose, which may cause gas or pain in your belly. Then your blood will be tested every 30 minutes for 2 hours. If your blood sugar levels do not rise, you may be lactose-intolerant. This test is not done on people who have diabetes. And it is usually not done on babies and very young children.

    WebMD Medical Reference from Healthwise

    Last Updated: March 12, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    1
    Next Article:

    Today on WebMD

    man holding his stomach
    Get the facts on common problems.
    blueberries in a palm
    Best and worst foods.
     
    woman shopping
    Learn what foods to avoid.
    fresh and dried plums
    Will it help constipation?
     
    top foods for probiotics
    Slideshow
    couple eating at cafe
    Article
     
    sick child
    Slideshow
    Woman blowing bubble gum
    Slideshow
     

    Send yourself a link to download the app.

    Loading ...

    Please wait...

    This feature is temporarily unavailable. Please try again later.

    Thanks!

    Now check your email account on your mobile phone to download your new app.

    Woman with crohns in pain
    Slideshow
    Woman with stomach pain
    Slideshow
     
    diet for diverticulitis
    Video
    what causes diarrhea
    Video