Avoid beans, peas, pulses, pasta and root vegetables for 48 hours before HBT (all increase amount of hydrogen produced in gut).
Teeth should be cleaned thoroughly before test. You will be asked to rinse your mouth with an antibacterial mouthwash before starting the HBT (bacterial in the mouth may produce hydrogen). This may be done at home after brushing your teeth: please let us know if you have done this already.
Do not chew gum before the HBT.
Cigarette smoking may lead to a false positive result due to carbon monoxide and must be avoided for 6 hours before HBT.
Broad spectrum antibiotics or bowel preparation (for colonoscopy, CT scanning, barium enema) may alter the bacterial content of the small and large intestine and must not be taken within 4 weeks of the HBT or a false negative result may be obtained.
Probiotics (e.g. lactobacillus, bifidus, acidophilus) in capsule, liquid or powder form are not allowed in the 4 weeks leading up to the HBT.
Avoid laxatives or stool softeners for 3 days before HBT.