Breath Testing

Breath Testing

  • Breath Test is a painless and non-invasive test which helps to diagnose the following gastrointestinal disorders:
  • small bowel/intestinal bacterial overgrowth.
  • lactose intolerance (lactase deficiency- milk sugars).
  • fructose malabsorption. (Fructose is a type of sugar found in almost all fruits, honey, and in many vegetables)
  • Hydrogen production and intestinal transit time.
  • sucrose malabsorption (sucrase-isomaltase deficiency)
  • sorbitol

How Do The Tests Work?

The procedure for each test (fructose, lactose, lactulose and glucose, sorbitol and sucrose) is simple. You need to perform each breath test on a different day.

When you attend each breath test appointment you will be given a hydrogen breathalyser type device to breathe into. This first sample is recorded, then you will be given a sugar solution to drink, after which another breath sample will be taken from you every 30 minutes over the next 2~3 hours. (Most people complete the tests in 3 hours, some complete it earlier).

The Glucose test takes 2 hour to complete.

Your referring practitioner will describe which of the test sugars (Fructose,Lactose or Glucose, sorbitol and sucrose - or any combination of these) you are to do. However, a baseline test, (a Lactulose test) must be performed prior to any of these test sugars, to make sure you produce enough hydrogen gas. If you are a low- or non-hydrogen producer with Lactulose, you will be changed from the breathalyser device to inflatable bags during the course of your test as these bags allow us to also measure methane gas. This will ensure that we capture whichever type of gas (hydrogen or methane) you produce.

How Do I Prepare?

A restricted diet must be followed a full day prior to each test. You must follow the diet strictly in order for the results of your tests to be usable.

One month before

  • no colonoscopy or barium meal enema procedures
  • no oral antibiotics.
  • no probiotic supplements containing lactobacillus, bifidus, or acidophilus bacteria (eg. inner health plus, ibs support, proflora).

The day before the test

The Pre-Test Diet: on the day before the test you can only choose foods and drinks from the list below:

If it’s not on this list, you cannot have it

  • Drinks: Water (unflavoured, uncarbonated), Lactose free COW’S milk, Rice milk, Coffee – Instant/ Plunger are okay, but no coffee substitutes (Caro, etc), Tea – Normal black tea with sugar (not herbal tea).
  • Breakfast Cereals: Corn Flakes, Rice Bubbles, Rice/Corn Cakes (plain)
  • Flavourings & Seasonings: Normal sugar (sucrose), Salt, Pepper.
  • Spreads: Nuttelex, Vegemite.
  • Meals: Egg, Corn/Rice Cakes (plain)
  • Meats: (Plain, no artificial colouring/flavouring) – Beef, Lamb, Pork, Ham, Chicken, Turkey, Fish, Seafood – you can cook in small amount of olive oil
  • Vegetables/Cereals: Bean sprouts, carrot, cucumber, zucchini, iceberg lettuce, sweet potato, tomato, baby spinach, turnip, squash, potato, pumpkin, rice, bok choy, celery.
  • Fresh Fruit: Banana, blueberry, star fruit, canteloupe, dragon fruit, grapefruit, kiwi fruit, lemon, mandarin, honeydew, orange, pawpaw, pineapple, raspberry, strawberry (max. 1 handful of any combination of these fruits in 2 hour period). No dried fruits.
  • Alcohol: maximum day’s intake prior to 9pm on night before test: DRY Wine – 120ml; Spirits – 60ml.
  • Please be aware that many canned and packaged foods/meals and meals at restaurants have sauces, spices, onion flavouring, artificial sweeteners, soy products, etc. which should be avoided.

PLEASE NOTE: Many chewing gums and sweets contain artificial sweeteners, and must not be chewed or eaten on the day of the diet, or in the morning of your tests.

DO NOT EAT OR DRINK ANYTHING ELSE - it could give false results for the test. Specifically, avoid beans, dairy, pasta, fibre cereals, high fibre foods. The night before the test, have an early dinner of rice and meat.

For 12 hours before your test:

You must stop eating and drinking 12 hours before the test. For example, if your test is at 9:00 a.m., you would stop eating and drinking at 9:00 pm the night before. You may continue to take your usual prescription medicines with water until 12 hours before the test.

The day of your test:

You should not eat or drink anything in the morning. If you are diabetic requiring insulin or diabetic pills, ask your physician if you should change your morning dose. Generally, half of your normal long acting insulin is given. Oral hypoglycemic medications are usually not taken that morning until completion of the test and resumption of eating meals.



  • A technician will explain the test to you. Ask them any questions you might have.
  • We will ask you to breathe into a bag or breathalyser every 30 minutes. You may need to do this for 3 hours.
  • You will be given a sugar solution to drink and we will measure samples of your breath.
  • The test is performed in a group setting and you may wish to bring reading material, laptop, etc. to occupy your time.

You may resume your normal diet immediately after your test. You may experience certain gastrointestinal symptoms as a result of your test, such as bloating, flatulence, or in less common cases, bowel motions. Side effects are not expected.