Treatments
Your doctor may suspect lactose intolerance based on your symptoms and your response to the amount of diary foods in your diet. Your doctor can confirm your diagnosis by conducting the following tests:
Lactose Tolerance Test:
This test measures your body's reaction to a liquid that contains high level of lactose. Two hours after drinking the liquid, you'll go to a blood test to measure the amount of glucose in your bloodstream. If glucose levels dosen't rise, it means that your body isn't properly digesting and absorbing the lactose-filled drink.
Stool acidity test:
This test are for infants and children that can't undergo other tests. The fermenting of undigested lactose creates lactic acid and other acids that can be detected into a stool sample.
Hydrogen Breath test:
This test requires you to also drink a liquid that contains high levels of lactose. Then the doctor measures the amount of hydrogen in your breath at regular intervals. If your body dosen't digest the lactose, it will ferment in the colon, realisng hydrogen and other gasses. which are absorbed by your intestines and exhaled. A breath test indictate that you aren't fully digesting and absorbing lactose.
(Mayo Clinic Staff,2015)