Gastrointestinal pathology theory defines structural and functional disorders based on the balance between mucosal protective factors (blood flow, bicarbonate) and damaging agents (acid, pathogens), classifying lesions into inflammatory states like acute/chronic gastritis or neoplastic conditions such as gastric adenocarcinoma. Malabsorption mechanisms are governed by infectious etiology causing villous atrophy versus non-infectious etiologies triggering immune-mediated mucosal damage, specifically distinguishing between bacterial infections (e.g., *Helicobacter pylori*, *Giardia lamblia*), protozoal invasions (*Entamoeba histolytica*), and antibiotic-induced toxin release. The core theoretical framework links specific pathological changes—such as autoimmune parietal cell destruction leading to achlorhydria, or diffuse infiltration causing intestinalis plastica—to distinct clinical phenotypes like megaloblastic anemia, signet-ring cell carcinoma, or ulcer formation patterns.
Gastrointestinal pathology theory defines structural and functional disorders based on the balance between mucosal protective factors (blood flow, bicarbonate) and damaging agents (acid, pathogens), …