Diet and Nutrition

How is Lactose Intolerance Diagnosed?

How is Lactose Intolerance Diagnosed?

Lactose intolerance has gained a lot of prominence in recent years. The common symptoms of lactose intolerance like bloating, flatulence, discomfort, and diarrhea can often mimic the symptoms of many other medical conditions. There is often a tendency to self-diagnose when observing these symptoms. Obviously, this can have potential implications if the symptoms are caused by other conditions. If you suspect you may be lactose intolerant, consult your doctor and request to be tested for the condition. Lactose intolerance can be diagnosed several ways. Many who suffer with gastrointestinal issues often assume that they are lactose intolerant, despite never officially being diagnosed.

If you think you or your child may be a victim of lactose intolerance, it is very important that you visit a doctor. Children are especially vulnerable to calcium deficiency, this can be caused by restrictions in the intake of milk and milk products in their diet. Getting diagnosed early and consulting a dietician to avoid nutritional deficiencies is very important. Before scheduling a visit with your doctor, consider what you eat and drink on a daily basis. Also, consider what symptoms you are currently experiencing. Inform your doctor of any food allergies you feel you may have. It is also important to inform your doctor of any medications, vitamins, or supplements you are taking. If you have any questions you would like to ask the doctor, be sure to write them down. This will help you better prepare for your consultation. To reduce the symptoms, it is suggested that you remove lactose from your diet for around two weeks. Doing this will help provide insight as to whether or not you are lactose intolerant.

Tests for diagnosing lactose intolerance

Accurate diagnosis of lactose intolerance is important, as it may relieve the patient’s anxiety and symptoms. Secondly, it avoids misdiagnosis and inappropriate treatments.

Dietary challenge

The dietary challenge is one of the ways to test for lactose intolerance. This is done by manipulation of the diet. The American Academy of Pediatrics recommends a lactose-free diet should be followed for up to two weeks. It is important to eliminate all sources of dietary lactose during this period. Carefully read all food labels to ensure that no lactose is present in the ingredients. If the symptoms resolve during this period, and return after reintroduction of lactose into your diet, then lactose intolerance can be diagnosed. However, it is important not to self-diagnose, as this can lead to deficiency of essential nutrients. Self-diagnosing can also result in a failure to identify other gastrointestinal issues. If the results of the dietary challenge are inconclusive, then further testing will be suggested by the doctor. Some of the laboratory tests for diagnosis of lactose intolerance are provided below.

Advanced testing

Although these tests are not of the highest importance, they may still be suggested:

  • The confirmation of the diagnosis
  • Analyze the amount of lactase produced by the body
  • Determine the possible origin of your lactose intolerance

Hydrogen breath test

A hydrogen breath test is an easy way of determining if you have lactose intolerance. Avoid food and beverages the night before the test. You will be requested to blow into a balloon-like bag at the beginning of the test. The sample breath test is used to ascertain the amount of hydrogen present, it is normally measured in parts per million. A drink of lactose solution will be administered. Your breath will then be tested every 15 minutes over the span of an hour.

The purpose of this test will be to determine fluctuations in hydrogen levels. If a large amount of hydrogen is found in the breath after consuming the lactose solution, there is a possibility you could be lactose intolerant. This is because the bacteria in the colon can produce abnormal amounts of hydrogen, resulting in lactose intolerance.

Testing lactose tolerance

During a lactose intolerance test, a lactose solution will be administered and a sample of blood will be taken from the arm. Glucose content will also be tested. In the case of lactose intolerance, blood sugar content will rise gradually, or remain the same. This is because the body is unable to split lactose into glucose.

Milk tolerance test

During a milk tolerance test, a glass of milk will be administered and blood sugar levels will be analyzed. If blood sugar levels remain the same after drinking the milk, chances are you're not lactose intolerant.

Small bowel biopsy

A small bowel biopsy is not commonly used to check for lactose intolerance. It is more often used to determine if your complication has been brought about by other conditions. During a small bowel biopsy, a sample of the intestine is taken with the use of an endoscope that is carefully lowered down your throat. This exercise is done with the use of a local anesthetic to avoid discomfort. The sample is analyzed to determine how much lactase it contains. If it has small amounts, you probably aren't lactose intolerant. The sample can also be used to identify hidden complications, such as celiac disease.

Stool acidity test/ Fecal pH test

In infants, the method’s mentioned above may be impractical and risky. In these cases, the stool acidity test is used. The procedure is as follows:

The infant is given lactose to drink. If the lactose is tolerated, then it will digest. If not, then the undigested lactose will reach the colon, where the action of bacteria will cause the stool to become acidic due to the formation of lactic acid and other acids. Stools passed after ingestion of lactose are tested for acidity. The infant is diagnosed as lactose intolerant if the pH of the stool is less than 5.5.

Genetic testing

Genetic testing helps in assessing whether a person has secondary lactose deficiency. It is also useful when it comes to differentiating IBS from lactose intolerance, both of which have similar symptoms. DNA extracted from blood or saliva is used to make the diagnosis. However, genetic tests developed so far cannot cover all the genetic mutations that exist within different populations.

To conclude

Lactose intolerance can be managed in most cases through dietary restrictions.

Key Takeaways

  • If you think you or your child may be lactose intolerant, it’s very important that see your doctor
  • Removal of lactose from the diet for around two weeks may be suggested by the doctor to reduce symptoms 
  • A hydrogen breath test is an easy way to identify lactose intolerance