This test is used to evaluate for small intestinal bacterial overgrowth, or intolerances to different types of sugars, such as lactose. The testing is safe, and easy to perform.

In small intestinal bacterial overgrowth, bacteria are present in larger than normal levels in the small intestine. This leads to increased breakdown of food, inflammation, and trouble absorbing nutrients, which can cause symptoms such as; bloating, abdominal discomfort, diarrhea, and weight loss. Typically, quite a few bacteria live in your colon, but not too many are present in the small intestine. The constant motion, pushing food along and the acid that enters the small intestine from the stomach, cause the bacteria levels to be lower in this area.

To test for this condition, a sugar, called lactulose is given to you. When bacteria breakdown, this sugar hydrogen is released. This typically happens in the colon. If bacteria are present in the small intestine, these substances will be broken down earlier and hydrogen will be released. The hydrogen level can be measured in your breath.

Lactose is a sugar that is most often found in dairy products. Lactase is the chemical present in the body that is responsible for breaking down lactose. With lactose intolerance, there are low levels of, or not properly functioning lactase. The decreased amount of lactase can be due to injury of the lining of the GI tract, or because of how you were born. If lactose is not broken down, it cannot be absorbed in the small intestine. This lactose then travels to the colon, and the bacteria present there break it down. This can lead to diarrhea, abdominal pain, bloating, vomiting and flatulence.

To test for this condition a specific amount of lactose is eaten and the amount of hydrogen in your breath is measured over time. Typically lactose is fully absorbed prior to reaching the colon so, if you have normal levels of working lactase, there is no increase in the level of hydrogen. But, if lactose reaches the colon, it is broken down by bacteria releasing hydrogen; the level of hydrogen you breathe out is measured.

How does this work?

You will drink a mixture of sugary water and then are asked to breathe into a plastic bag right away, and then every 30 minutes.

How long does the test take?

Your breath samples will be taken about every 30 minutes, and all together the test may last from 1-4 hours.

Do I need to prepare?

The day before the test, eat your normal diet for breakfast and lunch, except avoid bran and high fiber foods. Also, do not take Metamucil, Citrucel, Benefiber or any other fiber supplements.

The evening before the test, your diet should include any (or all) of the following:

  • Salad- lettuce and dressing only
  • Any type of meat or fowl
  • Jello
  • Any beverages
  • Rice
  • Ice cream
  • DO NOT eat potatoes, vegetables, bread, pasta, pastry, fruit

In the 12 hours before the test NO:

  • Smoking. Tobacco smoke has high levels of hydrogen so will make the test inaccurate.
  • Eating or drinking anything including candy
  • Chewing gum
  • Please avoid vigorous physical activity 2 hours before the test.

Bacteria present in your mouth can change the results so just before the test, you will be given mouthwash.

Can I take my medications before the test?

No. Please do not take any of your morning medications prior to the test, unless otherwise instructed.

Can I sleep during the test?

No. Sleeping causes the hydrogen levels to rise because this slows the movement through the GI tract.

What else should I know?

If you have recently been treated with an antibiotic or had recent episodes of diarrhea, please let the office know. Also, if you have lung disease your results may be difficult to interpret.

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