<i>Helicobacter pylori</i> (<i>H. pylori</i>) is the most prevalent bacterial pathogen that infects approximately half of the world’s population. It is well known that <i>H. pylori</i> causes chronic gastritis, peptic ulcer, and gastric cancer. <i>H. pylori</i> can also be associated with other gastrointestinal diseases. Epidemiologic studies have reported an inverse correlation between <i>H. pylori</i> infection and gastroesophageal reflux disease. However, the results of <i>H. pylori</i> eradication in patients with gastroesophageal reflux disease were not consistent with epidemiologic studies. Many studies have reported symptomatic improvement in uninvestigated dyspepsia and functional dyspepsia (FD) following <i>H. pylori</i> eradication, suggesting that <i>H. pylori</i> is the cause of dyspepsia. Therefore, it has been suggested that <i>H. pylori</i>-associated dyspepsia should be considered an entity distinct from FD and only the patients with persistent symptoms following eradication should be considered as having FD. A majority of studies also support an association of <i>H. pylori</i> with colon neoplasms and an inverse correlation with inflammatory bowel disease. However, no association of <i>H. pylori</i> with irritable bowel syndrome has been reported.
Helicobacter pylori and Other Gastrointestinal Diseases