Lactose Intolerance Breath Test

Submitted on March 27, 2012

Lactulose is a synthetic type of sugar that is commonly used in the treatment of constipation and a number of liver diseases. Just as with almost any type of medication, lactulose also comes with a number of risks such as the likely production of flatulence and intestinal cramping. The dosage of the chemical compound needs to be carefully monitored as an overdose could lead to a number of other complications such as diarrhea with the additional threat of excessive loss of fluid, hypernatremia and hypokalemia. Because of the problems arising out of an overdose of lactulose intake, lactulose breath tests are a fairly common treatment procedure that is used primarily to identify the abnormal growth of bacteria in the intestines. It is important to point out that, under normal circumstances, this bacteria will already inhabit the intestines. However, when the presence in the area is excessive, the intestines are unable to absorb food and nutrients properly. The overgrowth of this bacteria could be the result of factors such as a slow transit of food through the bowels as well as intake of medication including lactulose.


The breath test for lactulose is performed by the patient being asked to breathe into a breath collection device that collects and analyzes the exhaled air for the presence of hydrogen. Once this baseline sample has been collected, the patient is then asked to drink a solution of lactulose before scheduled samples of the individual’s breath are collected. This is done after intervals of about 20 minutes over a 2 hour period. A total of 10 breath samples is usually collected before they are sent to the lab for analysis.


Preparation for a lactulose breath test is rather extensive and requires the patient to avoid taking any antibiotics for up to about 2 weeks before the test. Any foods that are known to digest slowly such as coarse breads, nuts and beans should be avoided up to a whole day prior to the test. Other habits that one should avoid on the day of the test include smoking, eating heavily or even sleeping for up to ½ an hour prior to the commencement of the test. After the test has been completed, the patient will be allowed to return to his or her normal patterns of living and medication. The results need to be analyzed by a laboratory before they are discussed with a patient and the doctor will usually receive the data about 10 days after the breath test was performed