Current understandings of Helicobacter pylori, peptic ulcer and gastroesophageal reflux disease.

H. pylori infection is a major pathogen inducing gastric mucosal inflammation and causing dysregulation of normal acid inhibitory regulatory mechanisms. The overall effect on gastric acid secretion is dependent on the location and severity of inflammation. Eradication results in healing of gastric mucosal inflammation, healing of peptic ulcers, prevention of new peptic ulcers, prevention or reduction in gastric cancer risk and in transmission of the infection. Neither H. pylori infection nor H. pylori eradication causes gastroesophageal reflux disease (GERD). H. pylori eradication also does not impede anti-secretory drug therapy of GERD. Misunderstandings of the negative association between H. pylori infection and GERD and/or Barrett's esophagus and misuse of the epidemiologic concept of ''protection'' led to considerable confusion and likely resulted in some patients receiving poor care. Current evidence is consistent with the notion that H. pylori should be eliminated whenever the organism is found. However, H. pylori infection has become increasing difficult to cure in part due to the emergence of antimicrobial resistance. In Western countries, triple therapy consisting of a proton pump inhibitor, amoxicillin and clarithromycin no longer achieves adequate eradication rates and will soon need to be abandoned. When used, legacy triple therapy should be given for 14 days. Fluorquinolones may temporarily be useful: 10-14 day duration is superior to 7 days. However, worldwide resistance is rapidly increasing. Other potential replacement therapies and strategies are discussed including sequential therapies, high-dose proton pump inhibitor plus amoxicillin, and new quadruple therapies.