The article provides a comprehensive analysis of the etiopathogenesis of gastrointestinal diseases, emphasizing the complex interplay between genetic predisposition, environmental influences, microbiome dysbiosis, immune dysregulation, epithelial barrier damage and neurogastroenterological mechanisms. Modern research shows that GI disorders are not caused by a single factor but emerge from multilayered biological and behavioral interactions. Special attention is given to the role of Helicobacter pylori, dietary imbalance, chronic stress, immunological reactivity and structural abnormalities in triggering pathological processes. The review highlights current scientific perspectives and underscores the importance of integrating molecular, microbial and clinical data to improve diagnostic and therapeutic approaches.