Three primary tests evaluate lactose intolerance caused by a deficiency, which develops over time or by damage to the small bowel. Intolerance indicates a lactase enzyme deficiency causing undigested lactose to stay in your intestine and produce symptoms such as nausea, watery diarrhea, bloating and cramping. Only one test is necessary for diagnosis, each test using a different parameter to assess lactose digestion. A small bowel biopsy, not commonly performed, can confirm a questionable test result.
Blood Test
The oral lactose tolerance blood test calculates the amount of blood glucose after drinking a lactose solution. Digestion of lactose begins in the stomach, breaking down into glucose with intestinal absorption into the bloodstream. Testing requires an 8-hour fast, restricted exercise and a baseline blood sample, followed by a prescribed dose of lactose. Serial blood samples are drawn, and glucose is measured, with high increases indicative of lactose intolerance.
Breath Test
The hydrogen breath test requires breathing into a container that measures exhaled hydrogen, a gas, after lactose is taken orally. Normally you exhale small amounts of hydrogen, but with decreased lactose digestion, exhaled hydrogen production rises. The same test preparation for blood testing applies to the hydrogen test, with sequential breath samples calculated for hydrogen content.
Stool Test
Stool acidity testing measures the acid or base, called the pH, in stool and is well suited for infants and children, since consumption of large quantities of lactose is difficult for these age groups. Undigested lactose produces lactic acid in the intestine, as well as other acids, decreasing the pH in stool. Normal stool pH values are 7 to 8, but lactose intolerance lowers pH to 5.5 or less.
Treatment
There is no cure for lactose intolerance, but management is achievable by reducing dairy products in your diet. A potential therapy using probiotics in dairy foods and supplements can help relieve symptoms if dietary changes don't work. Probiotics incorporate strains of useful bacteria in foods and supplements that aid digestive disorders, including lactose intolerance. Remember to check for lactose ingredients in prepackaged products you already use.
Diet
If you're concerned about losing calcium by excluding dairy products, you can solve the problem by consuming other foods and products. Kale, broccoli, oranges, spinach, rhubarb and tofu contain calcium, and soy milk, rice milk and calcium-fortified products are also good sources. Reducing the amount of dairy products and eating them along with meals slows the digestive process and might decrease symptoms. Trying other dairy products such as cheeses might reduce reactions, and including lactose-reduced or lactose-free products can help.
