[Ulcerative colitis and Crohn's disease. Part 1. Definition, terminology, prevalence, etiology and patogenesis, clinical features, complications, classification].

Definitions of ulcerative colitis (UC) and Crohn's disease (CD) are given, related terminological problems are discussed, the prevalence of UC and CD in the population is considered along with their etiology pathogenesis, clinical symptoms, complications and extraintestinal (systemic) lesions. Classification and diagnostics of UC and CD are discussed with special reference to current international recommendations on their diagnostics and differential treatment.