Gastritis, most frequently defined as inflammatory reaction of the gastric mucosa to damage, is a complex multifactor pathologic process due to disequilibrium between the aggressive and defensive factors, dependent on the patient's humoral and cellular response. Gastritis is a problem still investigated intensively and still arousing much controversy. The questions commonly asked by clinicians are: how to diagnose the disease, whether, and how it should be treated. The authors discuss gastritis with a special emphasis on the clinical and morphological aspects. The term 'gastritis' comprises several groups of nosologic entities which can be divided into three main types - acute, chronic and atypical forms. The paper discusses the pathogenesis, diagnostics and treatment of these categories, as well as three main groups of drugs used in treatment: inhibitors of gastric secretion, antacids and drugs protecting the gastric mucosa. Particular emphasis is laid on the role of Helicobacter pylori infections in gastritis and the eradication treatment regimen recommended for pediatric patients by the Polish Operation Group for Helicobacter pylori Infections. Appropriate selection of doses as well as appropriate duration of treatment ensuring its efficacy and allowing to avoid adverse effects is especially important in children. The hypothetical correlation of H.p. infections with malignant tumors of the distal part of the stomach is an important aspect in children in view of the findings indicating higher risk of malignancy among patients infected at an early age.

Keywords: gastritis, children and adolescents, pathogenesis, treatment