- How the test is done
- Test result
- How to prepare for the test
- General Recommendations
- Recommendations the day before the exam
- Possible side effects
- Other tests that can be used
- 1. Lactose tolerance test
- 2. Examination of milk tolerance
- 3. Stool acidity test
- 4. Small intestine biopsy
To prepare for the lactose intolerance breath test, you need to fast for 12 hours, in addition to avoiding medications such as antibiotics and laxatives for 2 weeks before the exam. In addition, it is recommended to eat a special diet the day before the exam, avoiding foods that can increase the production of gases such as milk, beans, pasta and vegetables.
This test must be prescribed by the doctor and is one of the most used to confirm the diagnosis of lactose intolerance. The result is given on the spot, and the test can be done on adults and children from 1 year of age. Here's what to do when you suspect lactose intolerance.
How the test is done
At the beginning of the test, the person must blow slowly into a small device that measures the amount of hydrogen in the breath, which is the gas produced when you are lactose intolerant. Then, you should ingest a small amount of lactose diluted in water and blow into the device again every 15 or 30 minutes, for a period of 3 hours.
Test result
The diagnosis of intolerance is made according to the test result, when the amount of hydrogen measured is 20 ppm greater than that of the first measurement. For example, if on the first measurement the result was 10 ppm and if after taking lactose there are results above 30 ppm, the diagnosis will be that there is lactose intolerance.
How to prepare for the test
The test is done with a 12-hour fast for adults and children over 2 years old, and a 4-hour fast for 1 year old children. In addition to fasting, other necessary recommendations are:
General Recommendations
- Do not take laxatives or antibiotics in the 2 weeks prior to the test; Do not take stomach medications or consume alcoholic beverages in the 48 hours before the test; Do not apply enema in the 2 weeks prior to the test.
Recommendations the day before the exam
- Do not consume beans, broad beans, bread, crackers, toast, breakfast cereals, corn, pasta and potatoes; Do not consume fruits, vegetables, sweets, milk and dairy products, chocolates, candies and chewing gum; Allowed foods: rice, meat, fish, egg, soy milk, soy juice.
In addition, 1 hour before the exam it is forbidden to drink water or smoke, as it may end up influencing the result.
Possible side effects
Since the lactose intolerance breath test is done with the induction of an intolerance crisis, some discomfort is normal, especially due to symptoms such as swelling, excessive gas, abdominal pain and diarrhea.
If the test result was positive, see what to eat in lactose intolerance in the following video:
See an example menu and find out what the lactose intolerance diet is like.
Other tests that can be used
Although the breath test is one of the most used to identify a possible lactose intolerance, as it is fast and practical, there are others that also help to reach the diagnosis. However, any of these tests can result in the same side effects, as they depend on lactose intake to obtain their results. The other tests that can be used are:
1. Lactose tolerance test
In this examination, the person drinks a concentrated lactose solution and then takes several blood samples over time to assess the variation in blood glucose levels. If there is intolerance, these values must remain similar in all samples or increase very slowly.
2. Examination of milk tolerance
This is a test similar to lactose tolerance, however, instead of using a lactose solution, a glass of about 500 ml of milk is ingested. The test is positive if blood sugar levels do not change over time.
3. Stool acidity test
Usually the acidity test is used on babies or children who cannot take other types of tests. This is because, the presence of undigested lactose in the stool leads to the creation of lactic acid, which makes the stool more acidic than normal, and can be detected in a stool test.
4. Small intestine biopsy
Biopsy is used more rarely, but it can be used when symptoms are not classic or when the results of other tests are not conclusive. In this examination, a small piece of the intestine is removed by colonoscopy and evaluated in the laboratory.
