Patients should not have taken antibiotics or bismuth salts for at least three weeks prior to endoscopy

If the biopsy specimens appear to be very small, it may be worthwhile taking a third biopsy and inserting all specimens into Pronto Dry. Be careful not to contaminate the specimens with blood from the other biopsy sites

Helicobacter pylori has been shown to cause active chronic gastritis and has been implicated as a primary etiologic factor in duodenal ulcer disease, gastric ulcer and non-ulcer dyspepsia. 

By causing chronic inflammation Helicobactor pylori may weaken the mucosal defenses and allow acid and pepsin to disrupt the epithelium. H. pylori produces large amounts of urease enzyme. Although urease primarily allows H. pylori to utilize urea as a nitrogen source, the breakdown of urea also produces high local concentrations of ammonia, which enable the organism to tolerate low pH.