This test is used to diagnose lactase deficiency . During digestion, lactose is broken down into the monosaccharides glucose and galactose by the intestinal enzyme lactase. Lactose-intolerant patients have a deficient or absent lactase enzyme.
Bacteria metabolize the lactose, producing gas and acid products.
You are given 100 grams of lactose. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding . Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.