Helicobacter pylori is a gram-negative rod that can colonize the stomach. Infection with this organism increases the risk of peptic ulcer disease and gastric cancer. Transmission is thought to be by the fecal-oral or the oral-oral route, and people living in conditions with poor sanitation are more likely to be colonized with this organism.

The American College of Gastroenterology has published guidelines on the management of H pylori infection. Although they estimate that 30%-40% of the US population may be infected with this pathogen, most patients will be asymptomatic. Testing and treatment is recommended in only certain situations, including patients with a gastric or duodenal ulcer, gastric MALT lymphoma, or uninvestigated dyspepsia in younger patients without other alarming symptoms. Other situations in which testing and treatment may be considered include immune thrombocytopenia, unexplained iron deficiency anemia, and otherwise unexplained vitamin B12 deficiency.

Patients acutely infected with H pylori may be asymptomatic or may present with nonspecific symptoms including abdominal pain, nausea, vomiting, and fever. Symptoms, if present, typically last less than one week. Following acute infection, the majority of patients remain chronically colonized.

Gastrointestinal abnormalities that may result from H pylori infection include chronic diffuse superficial gastritis, gastric ulceration, duodenal ulceration, gastric adenocarcinoma, and gastric lymphoma. The symptoms that patients present with will depend on the specific gastrointestinal pathology that they develop. For example, patients with a duodenal ulcer may present with epigastric pain over the course of a few weeks. The pain is classically worse a few hours after eating. These patients may also complain of melena or hematochezia, as bleeding is a possible complication of ulceration.

Diagnosis can be made by biopsy at the time of upper endoscopy. Noninvasive diagnostic modalities include serology, urea breath test, and stool antigen test.

Treatment is with a combination of a proton pump inhibitor and antimicrobial agents.