Function tests

Gastrointestinal problems after lactose, fructose or sorbitol intake. Suspicion of bacterial miscolonization of the small intestine (glucose-H2 breath test).

This test is not suitable for children under the age of 8.

After oral load with lactose, fructose, sorbitol or glucose, the hydrogen (H2) concentration in the respiratory air is measured.

In case of intestinal malabsorption, the absorption process in the intestine is disturbed.

Unabsorbed sugars are transported from the small intestine to the colon. Here it is bacterially metabolized into molecular hydrogen (H2). The produced hydrogen diffuses through the colon wall and by circulation reaches the alveoli, from where it is exhaled.

H2 concentration in the expiratory air.

Exhaled air

H2 breath test - patient preparation:
Please read the following instructions carefully and adhere to the procedure.

The breath tests are carried out in our laboratory practice and take 3 hours. These tests are only carried out in the mornings from 0800 hrs, as you need to be empty-stomached!

Preparation:

• Breath tests are only possible in patients from an age of 8.
• You need to have been fasting for at least 12 hours, better 14 hours.
• Brush teeth the evening before and the morning of the test.
• Do not smoke (minimum of 6 hours prior to test and during the test)
• Do not have sweets or chewing gum during the test.
• You are not allowed to eat throughout the duration of the test.
• You are allowed to drink water and non-sweetened tea all the time (on the test day and the day before).

Meals:
On the day before the test

• You should not have carbohydrate-rich food 24 hours before the test (such as whole meal products, muesli, cabbage, onions, fruit, legumes/pulses, sugar, sweet drinks)
• Ideally the following is consumed: white bread, low-fat spread/cheese, margarine, rice, potatoes, lean meat, still water, black tea, coffee
• Last meal around 1800 hrs

Caution in the sorbit-breath test:
Preparation is the same as before, but

• No food products for diabetics are to be consumed before the test.
• No consumption of fruit, dried fruit, fruit juices
• If possible, use sorbit-free tooth paste

Medication:

• Antibiotic therapy should have ended 1 week prior to the test
• Antacids, stomach tablets and/or medication for heartburn should be taken no less than 12 hours before.
• 12 hours before the test no vitamin supplements are to be taken
• Laxatives, especially bulking agents (including lactulose) should be discontinued at least three days prior to the test
• All other medication can be taken on the test day

In patients with intestinal malabsorption there is a quantifiable increase in H2 concentration in the exhaled air after the test.