Lactose Intolerance
A Simple Breath Test

Jahn S. Hansen, MD
Gastroenterology
Eau Claire GI Associates, Eau Claire

Lactose intolerance affects more than 30 million Americans and is the most common of gastrointestinal problems. It is the body’s inability to digest significant amounts of lactose, most often found in dairy products. This inability results from a shortage of the enzyme lactase, which is normally produced by the cells that line the small intestine. Lactase breaks down lactose (a form of sugar) into simpler forms that can then be absorbed into the bloodstream. When there are not enough of the lactase enzymes to digest the amount of lactose consumed, the results, although not usually dangerous, may be very distressing.

Common symptoms include nausea, cramps, bloating, gas and diarrhea which begin about 30 minutes to 2 hours after eating or drinking foods containing lactose. The severity of symptoms varies depending on the amount of lactose each individual can tolerate.

When the lactase enzyme is missing, small amounts of lactose remain in the gut. The lactose draws water from the walls of the intestine causing them to become distorted. It is this process that causes the discomfort people suffer. If lactose is not broken down, it moves into the large intestine (colon) and the bacteria in the colon ferment the undigested lactose releasing hydrogen as a waste product.

For most people, lactase deficiency is a condition that develops naturally over time. After about the age of 2 years, the body begins to produce less lactase. However, many people may not experience symptoms until they are much older. The condition is most common in African Americans, American Indians and those of Asian, Mediterranean and Scandinavian descent. Researchers have identified a genetic variation associated with lactose intolerance; this discovery may be useful in developing a diagnostic test to identify people with this condition.

How do they determine if I’m lactose intolerant?

There is a simple test, available for children and adults. The hydrogen breath test measures the amount of hydrogen in a person's breath. Normally, very little hydrogen is detectable. However, undigested lactose in the colon is fermented by bacteria, and various gases, including hydrogen, are produced. The hydrogen is absorbed from the intestines, carried through the bloodstream to the lungs, and exhaled. In the test, the patient drinks a lactose-loaded beverage and then breathes into a device that measures hydrogen levels. The breath is analyzed at regular intervals over a three-hour period. Raised levels of hydrogen in the breath indicate improper digestion of lactose. This simple test can be easily administered in the clinic setting by visiting a gastroenterologist who specializes in diagnosis and treatment of disorders of the digestive system.

What if I’m diagnosed with lactose intolerance?

The symptoms are usually controllable through a change of diet. Avoiding dairy products and other foods containing lactose will solve the problem for most people. There are also over-the-counter lactase enzyme tablets and liquids that can be taken when ingesting foods containing lactose.

If you think you may be suffering from the symptoms of lactose intolerance, talk with your healthcare provider. They may refer you to a physician specializing in gastroenterology that can determine a diagnosis and suggest a plan of treatment.

For more information or to schedule an appointment with Dr. Jahn Hansen » 715.552.7303, Eau Claire GI Associates