Checking H. pylori requires fasting, avoiding antibiotics, bismuth, acid-suppressing drugs before checking, and should not be performed during gastrointestinal bleeding.
1. Fasting: patients check H. pylori mainly through blowing, measuring the content of carbon 13 or carbon 14 to determine whether the infection of H. pylori, if the patient is not fasting, can not guarantee the contact area of H. pylori and carbon 13 or carbon 14, resulting in bias in the measurement results.
2. Intake of antibiotics, bismuth, acid inhibitors: antibiotics, bismuth, acid inhibitors have a killing effect on Helicobacter pylori, generally if there is intake of drugs before the examination, there will be a part of the Helicobacter pylori killed, resulting in low measurement results. Generally stop using antibiotics, herbal medicines with antibacterial effect for at least 4 weeks, and stop using acid-suppressing medicines and bismuth for at least 2 weeks.
In addition, patients should not be overly nervous before checking for H. pylori, and make sure that the expiratory volume is sufficient in order to increase the accuracy of the measurement.